But why even use sign language? By now it's a proven fact that sign language can help reduce the frustration for infants and toddler as well as parents by empowering them to communicate before the child is able to speak. If you think now, well my/our child is already growing up bilingual and I/we don't want to confuse it with another language consider this. Sign language no matter if ASL or an other sign language can also be used as a connector between two or more languages. Even though a child hears the mother and father speak in two languages they do not yet understand all the words. When e.g. the mother speaks Cantonese and the father speaks German but they both use the same sign language it helps the child to identify the spoken words and connect them with the sign.
If you have questions or like more information about signing with children feel free to ask.