Yes, females do flare, they just don't have as big of a beard as males do usually.
And yes, a few VERY, VERY experienced keepers have kept SIBLING males and females they have bred together in very large well planted tanks, but that doesn't mean just anyone can do it or should ever do it.....and its not uncommon for these experienced keepers to have problems later down the road. I HIGHLY suggest separating them ASAP, because it is inevitable that either one will kill the other or they will both end up dead. So, either wait until one or both of them are near death or already dead before exasperating them, or do it now and prevent the inevitable and provide long, healthy, happy lives for them both. Your choice in the end.
I'm sorry to sound so harsh, but this really cannot be stressed enough. This species are FIGHTING fish, bred to fight and kill. Both genders just cannot live peacefully together under normal circumstances, even Sorority's are risky, have to be carefully monitored, and often run into issues.
Its really in the fishs' best interest if you separate them as soon as you can before you run into problems.