Tips on how to gain weight ?!

Yes you read it correctly, GAIN weight. I've been 90-95 pounds for years. When I was pregnant my highest weight was 120 and I loved being that weight. But I've been back down to 90-95 a little after I had my baby and now I look skinnier than before. My hip bones are sticking out and it looks so bad. I just want some meat on me. I hate being this tiny I always have. But I also don't eat more than once a day cause there's never food in the house and my mother never cooks. SO, can you guys help with ideas ???