I always found that when I put on a little weight I have a natural propensity to add them to the hips/waist area. The OH's waist stays the same but the thighs increase in size. Conversely, the last place I loose inches from is the waist.
We come in all shapes and sizes. The main thing is to find a weight you're comfortable with and get used to your body shape.
Scientifically speaking (and I'm no scientist) I read somewhere that people have different types of muscle fibre that do different things. That's why a naturally skinny individual will never become Mr Universe but could achieve a reasonable size with what he has. My advise .... be the best YOU can be. You'll be a lot happier for it. Stuff what other people think are IDEAL. That changes with time anyway.