My ego would get a kick out of this (especially since I'd like to get my own T into bed), but in therapy I'd be suspicious of statements like this as being insincere flattery. I don't like being patronized or patted on the head, and that's what this would sound like to me. I'd make that clear to her. (I'd also tell her "okay, you're on," but that's just me.)

I don't think that her telling you this is such a big deal though, I wouldn't consider it an ethical issue. I imagine that a lot of T's say things like this to their clients as confidence-builders, and it's probably helpful in many cases. I'm just saying I wouldn't like it, it doesn't sound like you're too comfortable with it either, so you should tell her that.