With Anavar being an orally taken steroid, unless your one of the lucky few that can find the injectable version, you have to remember the digestive track will dilute and filter a lot of it out before it actually gets into your system where it can help. 2.5 mg a day is like flushing it down the toilet. 5 mg a day will have some results, but since the smallest generally available pill available is 10 mg and oral Anavar has a half life of 9-12 hours in the system your going to want to take your dose twice a day at approximately 12 hour intervals. These 10 mg pills are tiny and cutting them in half to make 5 mg pills, is already next to impossible, so cutting them into quarters to give you 2.5 mg pills will end up leaving you a pile of dust and your dosing will end up being a little irregular. When my wife started it we just went to 10 mg a day with the pills being cut in half and 1 half pill taken every 12 hours.
I am not a doctor and my limited knowledge of females and steroids has been gained from reading and my wife's experiments with them. So take this as what that may be worth. I don't claim to be an expert.