Our Wylie has some disc disease issues - he was diagnosed about 2 years ago or so...? In that time, he's only had 3 "flares" where it's bothering him. When that happens, a vet usually has you give: a steroid, a muscle relaxant, a pain pill -- for about 7 days or so. And during that time, no fetching or hard playing or anything. But we weren't required to crate him or anything (my dogs don't even do crates anyways)...just to keep him from running or anything strenuous. All 3 flares resolved very quickly. I hope this regimen would work for your kiddo....my vet said it works in about 85% of dogs she sees.
I hope she feels better soon. I also hope Tink feels better too - how worrisome
!