If your wife has not used EAD despite applying for it
She can travel on her valid H4 visa, but she can as well use AP as she has it. From what I heard mere using of AP for travel does not cancel the H1/H4 status, only using EAD for a job cancels the H4 status. I do not see any problem in travelling esp when you have AP. But if u are expecting an approval soon, AP may not be valid once ur GC is approved..................