My 18 month old daughter has a full time nanny who has spoken to her only in Spanish (at our request) since she was 3 months old; my wife and I speak to her onl

My 18 month old daughter has a full time nanny who has spoken to her only in Spanish (at our request) since she was 3 months old; my wife and I speak to her only in English, and we don't speak any Spanish. It's been really fascinating to see what my daughter chooses to say in Spanish instead of English: always agua (her first word), siéntate ("sit"), mas ("more"), wacala (spanish slang for "yucky" - for poop)... other words, she can interchange depending on who she speaks to. Sometimes I can't understand her, and can't tell if she's trying to tell me something in Spanish, or her diction just isn't good enough yet. I suspect it's the latter, I think she's already adept enough at recognizing mommy and daddy don't speak Spanish...