Are there any other perks for donating other than the item you buy and no server que?
My gf also has an account. What gives the perks. Purchasing coins or spending them? It's my understanding I could buy them all on my account and gift her the coins I wanted to. If this is accurate would she also get the elevated account or do I need to make separate purchases?
#1 Queue skipping works for all realms but Lordaeron (on which you can get 30 days exempt by purchasing an item).
#2 Premium Membership. In some case the amount you have donated also matters, like when selling items on the trade market.
#3 Generally purchasing them. Gifting her coins would not grant her a Premium membership.