Your ex-fianc could marry here and then process for permanent residence abroad, but that may be difficult. Her stay expired or will expire 90 days after her entry. If she's here more then 180 days beyond that expiration date, she faces a minimum three-year bar to returning unless the INS grants her a waiver. Given her immigration history, getting a waiver might be difficult. No need to be embarrassed.
Love sometimes clouds the head.
Still, though you didn't ask me to, I withheld your name. I'm married to a U.S. citizen, but were are separated. My concern is my two kids by another lady who lives in Ghana. I'm originally from Gambia and recently I became a U.S. citizen. I want to take care of my children here.