Hi,
When you opened her mouth did you se a lot of mucus or bubbles?
I'm wondering if it could be thick, sticky, RI mucus causing it.
Dehydration might do it too for the same reason.
The only other thing I can think of is trauma to the tongue - do you have glass sliding doors it might have got caught in or anything?
And, just to double check, it was working fine previously?
dr del