Excuse the appalling pun in the title, but the lasses of English Ladies, flyfishing Association are sure to look after you.
http://www.elfa.org.uk/
In addition, although not in your neck of the woods, I know that Carsington water in Derbyshire run women only intro days:
http://www.carsingtonwater.com/Fly-Fishing0049v01.htm
Finally, despite reputational images (and some genuine examples!) to the contrary: not all male anglers are socially awkward dinosaurs with a penchant for patronisation. As in all walks of life, you'll find welcoming and well-adjusted groups of fellers in the strange mix that makes up the UK angling population.
P.S. Get the ELFA lasses to take you RIVER fishing
P.P.S. Join the Wild Trout Trust!!
http://www.wildtrout.org/
Denise Ashton is our Funding and Communications officer as well as casting a mean fly on a great variety of waters in the UK and abroad.