Why do kids whisper when you tell them to sign?

Jane is about 22 months old, and is starting to get interesting, language wise. She's my first child to grow up with enough exposure to sign language from birth for me to expect her to be able to use both languages well. And we all know how babies LOVE sign language, and can sign earlier than they can speak, blah blah blah....

Well, Jane is a verbal little girl. All my other kids were late talkers. Not Jane. She talks a LOT. When she was a year old, and I was signing "milk" like crazy to her, she just said it. It was kind of exasperating. This was going to be our little signing baby, dang it all!

I wonder if all that sign language helped develop her speech, actually...hmmm...

Anyway, at dinner, we usually do voices-off (unless we're all just really tired and can't bear the idea of having to think really hard). Except Jane, who talks along very happily. Ok, fine, Martha usually says what she wants to say, then Mom signs, "It's signing time..." and Martha signs it while whispering the same thing she just said. But at least she signs :)

Marriner and I have both felt like Jane could do better at learning to sign, and we're trying to encourage her to use her hands. This is what that looked like today:

While I was talking to Marriner, Jane wanted some attention, so she stuffed her sippy cup down her high chair, then shouts, "Mom! Milk!" I look at her (because even though my voice is off, it turns out I'm not actually deaf...) and sign, "What?" She says (again), "Mom! Milk!" Repeat this about 5 times. Finally, I sign, "It's signing time..." And I kid you not, Jane stops shouting and starts whispering.

Is she just copying her sister? Is there something inherent in hearing toddlers that they think signing is actually just talking really quietly?!?! Where does this come from? Don't they notice that their Deaf teachers still can't understand them when they whisper?!? Augh!!

So her milk is stuck in her high chair, and she doesn't want to sign. So I decide to help her. I sign,"help-me." Jane says out-loud, "Help me!" I sign, "Copy me: help-me" Jane says, "Help me!" Repeat about 5 times. Finally, I give in and talk. "Jane, sign help me." And she does. And then I help her.

Toddlers are weird.

Anyway, she understands what we sign to her, so I'm sure someday she'll decide to whip out those hands and use them. Until then, dinner will be a little funny.  Come to think of it, it will probably be a little funny after then, too!