PLEASE HELP - not losing weight on 1200 cal ....WHY?

I have a great set of scales that measure weight, water, bone and and percentage of fat. It tells me what each measurement should be between. The percentage of fat has gone up from 37% to 37.2% and all other measurements have stayed the same and in the right measurement frame. (except my % of fat and weight....they have changed).

those scales are inaccurate a lot of the time...I bought one stood on it and it told me I was 33% BF...I was not at that point I was 26%...

I don't care how great you think your scale is, it's just an estimate when it says body fat percentage, andbone mass and so on. You can't take it as an exact account, cuz it's not.

It's probably just water weight that you've gained. Are you weighing and measuring all your foods properly? If you are certain that your eating at a deficit, then you didn't gain "real" weight

^this

Some links to get you started:
http://www.myfitnesspal.com/topics/show/1235566-so-you-re-new-here
http://www.myfitnesspal.com/topics/show/1080242-a-guide-to-get-you-started-on-your-path-to-sexypants
http://www.myfitnesspal.com/topics/show/1234699-logging-accurately-step-by-step-guide

Do you weigh your food? Check to make sure you are logging accurately.
Give it time.

To gain a pound of fat, you'd have to eat 3500 calories above what you burn. You just have some inaccuracies in your scale - no big worries there.

Apart from that, your body will retain water from time to time for reasons that are inexplicable (some women gain around ovulation, ftr). Perhaps you are a bit constipated, perhaps there was some food in your stomach, perhaps the gravitational pull of the earth is different from yesterday. I'm not being snarky, btw. You can't get too worked up over small gains, which are temporary if you are otherwise accurately logging your intake and burn. I went up temporarily because I ate out at a restaurant, even though I hit my normal deficit for the day. It happens! Bodies are weird, and as much as we want to believe that they are precise machines, they aren't. If you see an ongoing trend over a couple of weeks, then maybe be concerned. Over a couple of days? Meh. Drink some water and cranberry juice and go low on sodium for a bit. It'll be ok.

Personally, I think you should try to increase a little bit and see what happens. Worst case scenario, you can always reduce again if you want. I eat @1500. I started at 202 lbs and am currently 135 lbs.
The reason I think you should try to maybe eat a little more, is that it's a more sustainable way for the long run, in my opinion. I'm in it for the long term success, so I try to make it more of a lifestyle change, rather then a diet. But either way, just play around with it a bit and see what happens. Sometimes we don't lose weight, but we are losing inches and toning. So weight isn't the only factor that comes into play. Do you track your macros?

I've seen a lot of suggestions regarding water weight as the culprit, and I agree it probably is, but if you're exercising more than you were, it could be some increased muscle, too. Muscle weighs more than fat, so if you're building up muscle, it could throw your scale weight off.

I eat between 1200 - 1500 calories per day and I've lost 25 pounds (11.34 kg) since mid-December on a mostly sedentary exercise plan, although I have been exercising (walking) more as the weather has improved.

Try check your weight once a week or every other week. I've had times where my weight has plateued for a week or two, even gone up a bit, then I'll have a big drop again. Also, try taking your measurements about once a month a so. Even if your weight doesn't seem to be dropping much, you may see a reduction in size.

How could it be muscle gain if she's eating at a deficit??

either way, I haven't lost a pound in months, but I've lost 4.inches in my waist and 2 in my hips. So yes, weight loss isn't linear, and she's probably retaining water.

I can't speak to diet, but I can speak to exercise, generally.

Physical Fitness 101
Exercise works best when it's inefficient. We go through what may be called an adaptation phase-- after which we become quite good at doing whatever it is we're doing and we plateau. So, what to do about it? Bring on the "overload" principle. We need to introduce new inefficiency: increase intensity.

Three ways to increase intensity:
1) Duration -- go further
2) Frequency -- go more often
3) Resistance -- go harder

Keep in mind, though during, these particular times of overloading, one's body does like to hold on to a bit more fluid during the repair process and/or when refurbishing glycogen stores. It's not uncommon to hold onto a few extra lbs after a particularly grueling session, but shouldn't last more than a few days. Five at the most. Salts, simple and complex carbohydrates and mild dehydration all have a chance to exacerbate this temporary weight gain.