Talking

When does a baby really start talking. My daughter is a year and two months and all she says is momma, daddy, no and all. She nods for yes and makes babble sounds but she doesn't say any words besides that. She watches super why and she loves books and puzzles but she's not really trying to communicate. She's has older siblings, but they don't really don't talk for her much. She just does her own thing. Almost potty trained though. I need ideas on how to get her to form words, or maybe I'm expecting too much from her.