As others wiser and more versed in Marvel lore than I have pointed out, JLA/Avengers offers the perfect out. Busiek establishes that DC chaos magic is vastly more powerful and dangerous than what Wanda is used to manipulating; she's overwhelmed the first time she touches it, and every time she uses it she gets visibly more weak and sick and fucked-up, as she struggles to hold on and her teammates worry desperately at each other.
Obviously, some of that lingered when she returned, the way Flash's Speed Force connection lingered for a short while after hopping over to 616, and it made her both more powerful and more crazy than prior characterization could possibly justify. No muss, no fuss, no chance of regression, and it can even explain Strange's patently false "there's no such thing as chaos magic" thing, like somehow he's understanding them to mean DC chaos magic, which of course there isn't such a thing, at least not in his multiverse.
The womb-crazy then just becomes some sexist idiot character's misinterpretation of events, and not the actual truth of the matter, alleviating at least some of the tedious sexism.