I think you should keep your plans to go ice skating unless she specifically says she doesnt want to go; i think it'll help to ease her mind off her heartache, and it'll give you guys some time to get to know each other better without looking like youre trying to move in.
As someone who is in a similar situation, i know this is gonna sound maybe kinda like a stupid idea, but honesty really works wonders with a girl; wait a while til things calm down with her ex and tell her how you feel about her but say that you dont want to seem like youre taking advantage of her bad situation.