Yes, all bettas have the ability to flare and females do too, they usually don't flare as much and as intense as males do but they still do "flare" without the ability for there little "beards" to get as large as males do sometimes
My female flares like crazy, far more than my male. She will flare if she catches her reflection in anything, and will go crazy trying to get at her reflection if I put a mirror up to her tank. She will also flare and jump up at things above the water (other than my magical hand of food - she waits patiently for me to drop pellets.)
I have a feeling she would chase down and kill any other females if I tried to put her in a sorority.
My male, on the other hand, is pretty mellow. He rarely flares and never jumps.