your first step sounds like a good one....do you have any kennel runs ??? I would then confine her and let the others loose (1 by 1 if necessary) to get acquainted through the fence -a crate is the second step if you don't have the run....
Leashes on all dogs - and prongs - during the acclimation tests period!!!
I would NOT - NOT under any circumstance let her loose with the older alpha female....even if not a dominate female, the younger one could decide that youth over age is a factor and you will have a fight...sooner or later - you will have a bitch fight, and that is not fair to the older bitch who will likely get the worst end of it.
Cats - some dogs will accept them fine, some will obsess....if she obsesses over them - protect the cat by separation.
Hexe Sch2, Komet & Kougar IPO1, Kira HGH, SG Bengal, Lynx v Wolfstraum ~ Ziberia IPO1 ~ ATB Basha, Kougar & Kyra, Fenja, Sch3s, Cito, Sch2, DangerRH, Csabre & Alice Sch1s ~Kelsey