I read in the past about some people who made a large laying bin, garbage can sized. Filled it with sand but not high enough for her to be able to climb out. Put a cover over it for safety and then really there isn't any where for her to go but down into the sand.
I think it was Jann B's blog post....not 100% sure
if she is just starting to dig around now, then I would say you have a little bit of time but you still need to act quick to solve the issue