As Blobmeister said, you have to spend something like 2/3 years in an infantry unit before you can specialize as a sniper. As females can't join the infantry I don't think you are able to become a sniper.
What if aj2608 were to pass AACC, then she (could be he) would then be classed as an infantry asset and technically i presume open to attend all the courses her fellow males would be allowed to. There have been a few case of All Arms Ranks passing the RM Snipers course. (Only a few mind, but still a few) Don't sniff so quickly, there have been a few female passes
wether who are entitled to wear the green beret and dagger....
The Russians love their female snipers. Pop a line off to old Vlad Putin he'll give you a job to do.
FFS is this person going to lead men? Thats the sort of daft question I'd expect from a 12 year old Army Cadet.