baby talking

My baby will be 11 months old on Tuesday she was saying mama dada baba able to clap, do so big, shake her head, & high fives no all of a sudden just saying mama and not following commands like when I say how big are you she would put her hands up and do so big and when I say clap your hands or shake your head she won’t is she focusing on something else or should I be very concerned im so confused as this is my first baby she is trying to stand alone at the moment