It would not bother me in the slightest, especially since it is not the first time she's responded to the statement. Plus you're reporting a dream "I love you." It's just acknowledging a fact. If it were the first time you'd said it, and said by real-art, not dream-art, it would be a poor response, yes, but I don't see how it is under the circumstances.

I kind of wonder if this is a sign of your attachment turning insecure again. A couple days ago you were talking and how much more mature and secure your relationship with her was. And yesterday you said that you felt you couldn't let yourself be happy in life without finding something to worry about. Same thing?