I knew something was wrong with my wifes diet plan.

You just be completely honest and tell you made her a "giant" by mistake. lol You can leave it as is, you can ask her to go cold turkey and stop eating the 500 extra, or you can wean 125 calories off her total each week for the next month. Losing 8lbs is still awesome though!

I'm confused...regardless of her height if she has lost 8 lbs in a month why wouldn't she continue doing what she's been doing?

This.
If she is losing on 1800, why cut it? Wait until she stops losing (for a few weeks, not just one or two) then drop it down a bit. No need to start out at the very bottom if its working at a higher and more managable level.

I don't understand how it was wrong if it was working.

^ Another for this. Two pounds a week and you think that she needs to go immediately lower? MFP, like all calorie counters, provides an ESTIMATE. It's not a magic number and if what she's doing is working, leave her alone. If anything consider a few more calories for her, but that obviously depends on her goals and where she is starting from.

I'm confused...regardless of her height if she has lost 8 lbs in a month why wouldn't she continue doing what she's been doing?

^^^^^^^That's a fantastic rate of loss. Don't change anything until or unless she stops losing. Two lbs a week is perfect!

Ok heres the deal. I keep track and log in my wifes info on her eating. Every time she attempted it she got frustrated and walked away. I was the one that set up her account. Today after reading about the 1200 cal concern i felt compelled to look at hers. -2 a week and she was at 1800+ cal. Ok something wrong so i did a check on the info i set her up with. OMG i set her height at 5' 7" instead of 5' 1". I feel like such an *kitten*. However even with my mistake she has still be able to drop -8 lbs in 1 month. But think about what i have done, setting the bar down is not an easy thing to do after being use to eating 500 calories more. Shes at work right now so she doesn't know. Not sure how to err break this error i made to her.

Don't change a thing!! It's working.
( smh at know-it-all men)

Ok heres the deal. I keep track and log in my wifes info on her eating. Every time she attempted it she got frustrated and walked away. I was the one that set up her account. Today after reading about the 1200 cal concern i felt compelled to look at hers. -2 a week and she was at 1800+ cal. Ok something wrong so i did a check on the info i set her up with. OMG i set her height at 5' 7" instead of 5' 1". I feel like such an *kitten*. However even with my mistake she has still be able to drop -8 lbs in 1 month. But think about what i have done, setting the bar down is not an easy thing to do after being use to eating 500 calories more. Shes at work right now so she doesn't know. Not sure how to err break this error i made to her.

Don't change a thing!! It's working.
( smh at know-it-all men)

^^^This except if she doesn't take control and do it herself she wont maintain this....SHE has to want it bad enough not to get frustrated and walk away...you can make it easier for her by setting up her meals and her food for her but beyond that time to walk away from logging her food...

I wouldn't change anything if it's working but I would tell her of your mistake just in case it stops working. That way she'll be prepared if she has to take on a bigger deficit. If this was her first month it's likely much of that 8 pounds was water weight so next month may not be as successful. Yeah, play it out at 1800 but definitely tell her now so that you don't have to tell her after another month of her being used to eating that much.

MFP's program presumes eating back exercise calories, and it is pretty terrible with that 1200 calorie thing. When your wife gets closer to her goal weight, maybe lower it, but right now, don't.

Your wife is 100+ pounds overweight, and she doesn't need to be eating 1200 calories to lose. You're in shape and have probably been through a couple bulk/cut cycles and know what it takes to lose at your body weight. Why would it be any different for her?

Setting aside the issue that she needs to figure this all out for herself and that she is more likely to fail with you taking care of absolutely everything, keep her at the 1800 calorie level because it's working. She will very likely lose on that amount for a very long time. Don't change anything until she stalls. And by stall, I mean when her rate of loss is zero.

Leave it as is. Really, you want to be able to eat the maximum amount while still losing weight.

If you insist she eat 1300 calories when she's been doing fine on 1800 calories, she's going to turn very b!tchy...if not from you messing it up, then from not eating enough. Too big a deficit will affect everything, especially her mood.

Ok heres the deal. I keep track and log in my wifes info on her eating. Every time she attempted it she got frustrated and walked away. I was the one that set up her account. Today after reading about the 1200 cal concern i felt compelled to look at hers. -2 a week and she was at 1800+ cal. Ok something wrong so i did a check on the info i set her up with. OMG i set her height at 5' 7" instead of 5' 1". I feel like such an *kitten*. However even with my mistake she has still be able to drop -8 lbs in 1 month. But think about what i have done, setting the bar down is not an easy thing to do after being use to eating 500 calories more. Shes at work right now so she doesn't know. Not sure how to err break this error i made to her.

Don't change a thing!! It's working.
( smh at know-it-all men)

I probably think this post is about me . . . lol

You're so vain, I bet you think this post is aboout you, don't you?

My question is, why isn't she doing this herself?

That's what I was thinking. It's her body, her weight loss. By doing her logging for her, you're depriving her of the opportunity to learn how her own food and exercise choices effect her own weight and health. Are you doing this secretly and controlling her diet without her knowledge? Or is she passively doing what you tell her to do in hopes that you'll fix it all for her? Either way, she should be doing it herself and have total control and ownership of her own life.

I'm confused...regardless of her height if she has lost 8 lbs in a month why wouldn't she continue doing what she's been doing?

^^^ this

also, the difference in the amount of food shorter people need to eat is not actually all that much, if anything errors in the activity factor would count for much more. And they don't take frame size/lean body mass for height into account (Katch McArdle does, but it also doesn't bother with height) I'm 5'1" and large framed and probably have as much lean body mass as many women of 5'7".

and the fact that she's succeeding tells me.... if it ain't broke don't fix it... if/'when the number of calories she's set to stops working, then worry about it. It's actually possible that the number for 5'1" could have been too low for reasons other than height (e.g. more activity, greater lean mass for height, etc) and your mistake gave her a better number of calories for her.

Let her take control, man.

After 46 years of marriage I have learned it is best to blame it on someone else like a computer glitch.

Okay, like everyone else is saying it is working. I'd tell her of the mistake, but also say, "But for now your calorie level is working, lets recalculate if you stop losing."