My 12 yo DD just recently came home from a Spanish exchange, and is now fluent in two languages. I am sitting here, listening to her chatting on the phone with her Spanish mama, and how fluidly she moves from Spanish to English (calling out to her brother, etc). It's wild.
I took Spanish as a youngling, but never reached that level of fluency; DD has said she will be my teacher! I am loving listening to her chattering away, and am excited for our next family holiday to Spain. :)
Are you bilingual, or do you have bilingual children? Will this feeling of awe go away at all? (she thinks it's "awesome" that she's better than me at something!)