Help for my good friend please?

I have a great friend and she is a girl. She is pretty big. Her belly is the biggest part of her and it is round and hangs about an inch. She is very beautiful and I love her size. Her hair is gorgeous as well. It is long, blonde, and curly. But recently, she has been gaining a ton of weight. Every time I see her about once a week, she just seems a heck of a lot bigger. Her family is very poor and she can't afford a lot of new clothes, so she has only 2 pairs of pants that fit her. She has sweat pants and strechy ones. She needs to wear an extra large in a t shirt, but she wears a medium thinking it will make her look skinny. In the past month, her belly seems to be showing skin below her shirt and she has the biggest and boldest stretch marks I have ever seen. She truly is gorgeous, but I am starting to worry about her health. I really like her as a person, but that belly (though I like girls with hanging bellies) is getting enormous. What do I do?