Tips on getting thicker?

I’m 5’4 & weigh 130 lbs. Everybody tells me I look fine but I’m not comfortable in my own body.. I used to be 85 lbs then I had my first daughter. Weighed 275 lbs when I was in labor. Believe it or not, I only got stretch marks on my hips! I went down to 120. Got pregnant with my second 3.5 years later. I had a c section in July 2017. I want to be at least 200 lbs because my weight goes to all the right places. I want to work out but I feel that I would get too skinny & I have a pretty decent size butt so I’d like to keep that too 🤣 if you ladies have ANY advice, tips, suggestions, PLEASE let me know!! Thank you! 💕