Oh, Hayleyb, that's such a tough situation.
How long will you be in Wales? It's so hard to say how quickly the end will come...every dog is different.
Have you talked to Oeskes' vet? The vet might be able to give you more insight into how she's doing and what your best course of action might be.
I'd also have a heart-to-heart with your friend who will be taking care of Oeskes while you're gone. If this is person you trust implicitly and who Oeskes loves, then even if the worst happens, you'll have comfort in knowing that she's in the best of hands, but make sure you're both prepared for it.
You and Oeskes are in my thoughts and prayers.