Well, early on, it won't do much. Little things will change around her. When she sleeps, it's at it's strongest. So, if it's a nightmare, the atmosphere around her will change. Things will decay around her but when she wakes up, everything will be back to normal. If she's day dreaming, the things around her will be affected until she snaps too. If she ever starts to get an understanding of her powers, she'll have to figure out how to make it work without it being while she sleeps or day dreams. She doesn't/won't know how to force it out of her. 

I'm not sure what powers he should have. He can really have anything you want him to. Plant manipulation, dark matter, light matter, healing spells (these would be nice considering Jena will probably be getting hurt a lot because of her personality. ). Just whatever you want.