Leah is able to sign a few things these days - more, milk, finished, water, up, etc. Luke has been really good about signing "daddy" whenever he comes into the room, but I guess I haven't been quite as diligent about "mommy".
For the last few days, when Leah gets fussy and wants me to hold her, she's been smacking her chest. Once I pick her up, or just come by her, she's fine. I couldn't figure out why she had chosen that sign (since she signs for "up" specifically when she wants to be picked up) until I caught myself saying "mommy" over and over again (in an attempt to connect her mamammaamamamamas to the "mommy" word, while patting my chest. She looked at me, and started patting her own chest.
So I inadvertently taught her that the sign for mommy is patting your chest. Oops. Not a huge deal, except that it may make any signs involving "me" or "I" sort of confusing.