>>1640292also a note
a lot of better rigid 90s mtbs are quite long, and womens often have pretty short reach. If you feel the reach is too long on a bike like that, it's very easy to correct with a swept back handlebar like pic related, and all the parts just bolt right over to it.
So for fit, not being able to get over the top tube, or having the seat set correctly for leg extension, and it being slammed or near slammed, means too small, but reach is easily corrected by converting to a cruiser bar, infact this improves the bike for city riding and makes it look cooler
Big choice on aliexpress for like $20 each too.