Gaining

That’s a worthy goal indeed, but I’m afraid a lot of it is genetics if you have otherwise decent health.

Your main profile pic is quite lovely, though, so you’re not exactly lacking in the beauty department :-)

I actually work out daily mostly because of trying "fat targetting". Normally, I would gain everywhere, including my ass, which may be hot on a girl, but I didn't like it on myself the first time around so I slimmed down and tried a different approach.
Working out, it seems my upper body grows as well as my belly, so yay!

It's mostly genetics. No amount of targeted exercise or dietary changes will turn an apple into a pear, or vice versa.

To put noticeable weight on the hips and thighs, the OP will need to accept a bigger belly to get there.

Which unless health, comfort, or relationship issues arise as a result, should not be a bad thing.

Unfortunately it is mainly genetics. I want wider hip and a bigger butt. But I am very happy with my big fat belly.