Help gaining weight?

Okay so I am a female, 5'6 or 7' and weight about 116lbs. Most people say I need to gain weight. Since I workout most of my weight is muscle and little fat. I've had a few doctors tell me to put on some fat..

BUT it seems like when I gain any weight it all goes to my butt and thighs even though I much more in need of it in my shoulders and my face. Does anyone have any tips for gaining fat/muscle without getting back the cellulite that I had worked so hard to get rid of?