Hmm,I'd have to say MOST of the time,YES,all she does to Ed,try to tattle on him,while Jimmy she's always trying to take care of him when he's hurt,he takes care of her while she's sick,with that she was trying to blow Ed off,in that episode when Sarah was sick,So Yes,I think She Treats Jimmy more like a brother than she does Ed.

When I first started watching the show, I immediately thought her and Jimmy were siblings. Then, when I learnt Ed was her brother I jumped to the conclusion that all three of them were siblings!

Ed and Sarah have had their brother/sister moments too, but I do think she treats Jimmy like a brother much more than Ed.