[LunarBerry]

I had my girl spayed in Dec. Blood work, catheter, and pain meds were on the optional list, but I went with them all even though it costed more cause they were not optional to me especially the pain meds lol I had one coworker tell me their vet didn't even offer/mention pain meds as an option. So be sure to let them know that you want the blood work and pain meds (catheter I was 50/50 on but figured why not, better safe than sorry). Blood work will help find any abnormalities that may affect her in surgery or the anesthesia, the catheter is kept in during surgery incase she has a reaction and they need to pump meds into her. Of course, every vet's procedure is different. I'd discuss what they will be doing.
After surgery, my girl was big hot mess, yours will be out of it for a bit but that's normal. She may have some blood tinge her urine for the first couple of days but it shouldn't be heavy/bright or getting worse. If it does get worse or has a lot of blood you'll have to get her to the vet quickly. Make sure she doesn't play around, run or jump. She'll be mostly recovered within 2 weeks (when stitches get removed) but will not fully recover until one month has past.