lost my hiney

my mom told me that if I unscrew my bellybutton my butt would fall off..

you didnt happen to unscrew said bellybutton, did you?

eat at a surplus and lift heavy weights

You don't have to lift heavy. You just need to do workouts where you do weighted exercises. I use my own body weight and no more than 5 pound hand set and am seeing progress I'm happy with. I'll build from there and don't like gyms.

Look up the "NoNonsense 30 Day Challenge" group. It's basically called "circuit training". I've lost fat in inches and gained muscle in muscle group areas while doing it. Everything, you can do at home in about 30 minutes. Similar to results from Jillian's 30 Day Shread, a $10 video that will also help build muscle while attacking fat.

Squats. Eat enough to build muscle.

Do squats.

You don't have to lift heavy. You just need to do workouts where you do weighted exercises. I use my own body weight and no more than 5 pound hand set and am seeing progress I'm happy with. I'll build from there and don't like gyms.

Look up the "NoNonsense 30 Day Challenge" group. It's basically called "circuit training". I've lost fat in inches and gained muscle in muscle group areas while doing it. Everything, you can do at home in about 30 minutes. Similar to results from Jillian's 30 Day Shread, a $10 video that will also help build muscle while attacking fat.

It's a misconception that one builds muscle while losing fat. While there are a couple of exceptions, building muscle means adding mass. That means adding a surplus which counters losing weight.
What's really happening is that fat is being reduced and muscle one's never seen is being "revealed" giving the misconception that muscle is being built.
Also to build muscle, resistance must be progressive for overload.
Circuit training builds muscle endurance.

QFT, also put in a much nicer manner than I would have.

Eat slightly above maintenance and go lift

I'm in a similar position. A few years ago I lost about 18 pounds at about 1 pound a week, and I completely lost my butt. Then I slowly regained much of the weight but it came back as a spare tire around my middle. So, thick middle + no butt = no good.

I am an older lady like yourself, and I think that has something to do with it. In the past, I used to gain and lose weight evenly all over my body. Now it all wants to clump around my middle and my back. Yuck!

I am finally losing some of that middle now, and here's the thing-- trying to regain some semblence of butt via targeted exercise to build those muscles. The only other way I know of is surgical implants, but that's not gonna happen!