I Love Being Skinny But How Can I Build Muscle And Tone?

I’m 5’2 and weigh about 110-115. So, I’m pretty petite, but also curvy. I’m not a twig like I used to be at 15, 16 lol. I’m 22 now. My measurements are 34D-24-34. I’m thin and curvy, which is great but I want to be more toned and defined. Like, my stomach is kinda pudgy and I finally have weight in my calves and thighs, but they jiggle! Also, in my arms. They’re bigger but they jiggle! I still have small wrists and small ankles. I have some hips but I feel they’d be more defined if I had a flatter stomach. My midsection is so tiny. I eat alot sometimes but sometimes I eat very little. I always try to eat healthy. And I exercise every once in awhile by doing dances from Just Dance on Wii. Should I just do this more often or does anyone have tips for me? Note: I used to dance, cheerlead, play sports, etc. So, even though, I’m glad I’m not as skinny as I used to be, I DID like that everything stayed in place and didn’t move. I love my curves but I need them in the right places ONLY.