Hi kittyuk! Welcome to GC!
I'm an alumna initiate also, and I think it's wonderful you're pursuing alumnae initiation. I see many have already given you some suggestions, and that you already have an idea which organizations you're interested in. Definitely e-mail the director of alumnae relations of each organization, and let them know you're interested in becoming an alumna initiate. Also, have them "introduce" you to the nearest alumnae chapter.
Ooh, I'd so love to go to England. Lucky you!
Keep the posts coming!