About 7,000 Servicewomen served in South Vietnam, mostly Army, Navy, or AF nurses, though there were WACs, WAFs (Women in the Air Force), and even a few Women Marines (yes, that's what they were called back then). There are a few possible scenarios for women to come under fire and return fire: I'll run through a couple.
Scenario A: MEDCAP (Medical Civic Action Program) run to a village. These usually had a doctor and a couple nurses, plus corpsmen, and an infantry squad, sometimes a platoon, for security. The "hearts and minds" concept at work...anyway, one of the smaller groups could easily have been ambushed, the villiage they're visiting is attacked, etc., and several of the grunts go down. One of the nurses grabs a weapon and returns fire. After the VC or NVA are driven off, the event makes headlines, she's known as "The Annie Oakely of Southeast Asia," yada, yada. Rotated back to the States early, Silver Star, etc.
Scenario B: AF Jolly Green Giant helo. These big air rescue choppers often made trips from SVN to Thailand, and an AF nurse or WAF hops aboard to hitch a ride to visit a boyfriend at whatever base: Udorn, Korat, or Nakon Phanom in Thailand, or Da Nang, Phu Cat, or whatever, in SVN. Helo is shot down in SVN and everyone, Pilots, Crew Chief, PJs, and the nurse passenger have to fight off the NVA or VC hoping to send the whole bunch up the Trail to the not-so-comfortable accomodations in the Hanoi Hilton. One or two of the crew get killed, another two get wounded, but the nurse and a couple others fight off the attackers until help arrives. Same thing follows: mucho attention in the press, early rotation back Stateside, decoration with Silver Star (or Bronze Star with V Device at least), and so on.
Double the media attention that follows if the nurse in question is captured and held until Operation Homecoming in 1973 and the full story about said fire-fight emerges.