How can I help my girlfriend gain weight?

My girlfriend is very skinny and id like for her to gain some weight. how do I get her to eat more or work out and get muscle mass or which ever way will make the scale go up. I love her but this is my only hang up. how do I go about 'helping' her gain weight.

that depends on if she NEEDS to gain weight or if you WANT her to gain weight. But I think the best way to get into shape (I'm sure you don't want her to be fat) or gain muscle mass is with a partner... so maybe you should suggest a co membership to a gym, start making meals high in protein or even just suggest going on walks together... thats a start.