This is pretty easy – they’ll have to. If you ever leave a signing baby with non-signers, they quickly discover that they are at a huge loss for not knowing the signs baby is making. Babies who sign will not stop signing just because someone else doesn’t understand them, they just continue on as if nothing was amiss. If this persists long enough though, eventually your baby will stop or reduce signing and this is the real issue. If you’re just dropping your baby off at Grandma’s house for a little while, she’ll be the one left without, but leaving a singing baby with a sitter during the work-week will inhibit signing progress significantly.
The best you can do is provide your caregiver with a list of the signs your baby already knows. Next, and if you caregiver is onboard, give them a list of signs that you are working on. You’ll want to take 5 minutes and have your baby show your caregiver their version of the signs as well as the proper signs – if they are significantly different. If you just show your caregiver the correct sign, they might not understand your baby’s version. If possible, take a short video on a digital camera and upload it to their computer so they can see for themselves and review it when necessary. Be sure to do some sort of voice over as your baby signs.
While you can’t force your caregiver into signing, you can choose a caregiver who signs already or one who’s willing to learn. In most cases, once they see the power of baby sign language, they’re likely to take over and teach the rest of the daycare. Now you’ve got a signing caregiver for life! Don’t be surprised if your baby comes home teaching you a thing or two.