My little girl is almost 13 months. She is attending daycare twice a week (and has been for a couple of months now) where they are using baby sign language. She has a few words that she says often and with meaning (Mummy, bird, hello, baby), she babbles a lot and will also sometimes copy a word she hears, but not always. The only "official" sign she is using is for "finished", but I have noticed that she is starting to use gestures for "gone", "bye" and a few other things, rather than saying the words. I confess I don`t know much about baby signing, but was hoping you could shed some light on whether I should be concerned that she might delay using words if she knows a sign to express what she wants.
In relation to baby sign language delaying speech, this is not the case. Research has highlighted that baby sign language actually accelerated the speech process. A very important part of introducing baby sign language to your child is to say the word while signing the word. The idea is that you are encouraging speech.
It has also been noted in research that children exposed to baby sign has a vocabulary of 50 more real words than non signing children by the time they go to speak.
If you would like to read more about the research, you can read it all from my website here. Also if you are interested in learning more about baby signing and implementing it at home, my book or dvd is a step by step guide on how to do it and incorporates Australian Sign Language.
For more information on my products, you can visit http://www.australianbabyhands.com/baby-sign-language-products/