G'day
If you want to work for the RFDS you are better off getting some remote area time. Instructing is good to get the initial build up of hours but I know the RFDS do look for remote time as well. It shows them a couple of things. 1. You are familiar with what the remote stuff entails and 2. you won't be so shocked when based in Derby, Mt Isa etc (when you get there you'll know what I mean).
Your age won't be an issue if you have a mature head on your shoulders. Broome is a good spot but usually the "nicer" the area the greater number of UGALs hanging around. I lived in Broome for over 2 years. Your gender won't be an issue unless your precious about it. You'll be expected to get your hands dirty and so on. Broome Aviation has employed female pilots in the past.
230 hours is low but that's what it's all about. If you get there early in the season, (like around Feb) and get yourself established then it should work for you. Note, no guarantees.
If you have other skills like computing, languages, engineering highlight them. If you can score about 10 or so hours in a C210 or similar before heading out then it will be useful.
Good luck and take a camera with you. Broome's wet season thunderies are something to see.