H visa holders with pending 485 don't necessarily have to have AP to leave and come back to US as long as they have valid H visa when they return.
One way for your wife to file 485 is when you are ready to file 485, your wife comes back with H4 visa and you two file together. After she receives the receipt notice, she can make short-term, multiple trips with H4 visa (she needs to apply for H4 outside USA). But if she plans to stay overseas till her case is abjudicated, it is gonna be a problem.