You can catch her on route 103, really rare though so look hard! :)
Yes, the female nidoran is blue and male nidoran is purple
Only On FireRed LeafGreen.
At The Pokemon Safari In Fuschia City
Nidoran female and male, evolve at lv !*, ther to evolve it to Nidoqueen or Nidoking, respectivly, get a Moon Stone! Sory,meant Lv 18 ------------------------------------------------------------- Your right about moon stone, but its lvl 16 that nidoran female and male evolve<< Signed Megadeth987
It is impossible to catch a male or female nidoran in Pokemon Ruby. To get one you'd have to get it by trade.