I said "I'm fine, I don't have much to say given the situation. It's nice that you're doing these things, I just don't have anything to add".
I'd have stopped at "...given the situation" lest you appear to be onboard with her useless & mindless wandering but if your tone wasn't bitter then yes, that was fine. She'd just use bitterness to say you aren't "growing", you know. If I were you, I'd shoot for indifference. And fake it til you make it.
I wonder how privileged your conversation with Dee was???