Intellectual theft by a colleague, how to respond?
It sounds like your adviser is already on the case -- let her handle it. She may know the colleague better, may know better how to handle such situations, and is in a position where she may not care about consequences any more if she calls out the colleague about the issue (because she already is a professor). You, on the other hand, do not have this luxury and consequently would be better off letting someone else handle this as long as you think that it is handled in a way that goes in the right direction.

So, rather than being involved yourself, let her handle that and keep you updated as to what is happening.