A few days after the thank you's, the pleases started.
When she wants something, she puts her hands up and says "eeeeessshhhhh!"
I must admit, it took me a while to figure out what she was saying; then one day she took a packet of crackers out of the cupboard, handed them to me and said "leeesh!"
She's now figured out that you need to say "please" if you want something, and she uses it more than she says "thank you."
"Thank you" is still used, usually only with my sister; if my sister gives her anything, she says "aah-doo!"
And now I'm really excited to see what her next word will be!