When you adopted her, did you take any time to just spend one-on-one with her before resuming your usual class/work schedule? Both times I adopted a shelter dog, I took a few days off to get as much social time in as possible before getting them into the usual "stay by yourself all day" routine. I know sometimes it's not feasible to take whole days off, but if your schedule is fairly hectic she might really just be craving some steady face-time especially since she's young and may not have a lot of socialization under her belt.
As for advice on the crating/separation thing, I've found a familiar toy can help out but even more than that I suggest giving her a "security blanket" for her crate. It need not be an actual blanket, just something that smells like you and that you don't mind having destroyed (like an old t-shirt or sweatpants). The scent + cuddle association can do a lot for separation.
I've also heard, but have no experience with, the idea that you should NOT overdo your goodbyes with a SA dog. Make your comings and leavings low-key. Put her in her crate with a "good girl" if necessary and then walk out the door. When you come home, let her out but don't cover her in kisses until she's calm. Lavishing attention on her when she comes bolting out of the kennel may be inadvertently encouraging her to be a nervous wreck when you arrive. You want to show her that you coming and going isn't a big deal.
You said she goes to the dog park, but do you take her anywhere else with you? I try to make special trips to the local Ace (they allow dogs), and of course there's always PetSmart, PetCo, etc. Lots of pet-food stores will also allow dogs on a leash and even some large retailers like Home Depot are pet-friendly. Even if I don't buy anything, it's bonding time that's important in social development.
I do have a question ... when she breaks out of her kennel, where do you find her? Couch? Bed? At the door?
~Marrow