UPDATE: She's talking now... YAY!!! Yes, she is talking... it was pretty sudden, but all of a sudden she just started repeating things when we'd ask her say them. Please, Thank you, down, hi, bye, mama, poppa, gracias... I'm no longer worried!!! She's on the right track!
My son did not say any words at 18 mos. In fact even at age three he could not say momma or dadda. He would just scream out. Finally at about 3.5 he began to talk. He's five and a half now, so he has really been talking for about 2 years and he has come so far in his speech. he learns new words everyday.
Thank you for your response. When we use signs, we of course also say the word. So we'll ask her "Do you want some milk?" and we do the sign for milk. It was initially intended for our daughter to be able to communicate with us when she was very young and still couldn't talk, which we achieved. But now she is still not saying much. Her hearing is fine, and being that she does say "yes" "no" "mama" and a few others the doctor is not concerned.
I have stopped teaching her new signs and I no longer use them when I speak to her. So hopefully she will start using more verbal words very soon!
Turtle, I'm curious about why you and your friends taught your children signs rather than the traditional pattern of verbal communication. Was she progressing apparently normally and for some reason you and your friends decided to teach children signs rather than voice words? I would think that would very much delay her ability to communicate with the hearing world.
Have you had her hearing thoroughly checked?
It seems that your friend's children also experienced verbal delays - talking by 18 months instead of the very typical 12 months.
I would be really tempted to stop using signs, completely ignoring the signs as if you don't understand what they are.