hun as a surviror myself 6 months post stem cell transplant (bone marrow cancer) I say YES! you have been through so much a little glass of wine is not going to have any impact long term. If you are on painkillers or other stuff it may make you a bit more drowsy so don't operate any equip. or drive ;).
Sure.
As long as it's only one glass.
Alcohol depresses the immune system and it is not a good idea to partake while there are wounds healing susceptable to infection.