Question about blood transfusions

[trambopoline]

Im not sure where to put this so I put it here. A family member of mine needs a blood transfusion, and im the only one with her type of blood. Is it alright to give her my blood even though I regularly smoke (not cigarettes)? If not, how long must I not smoke before the stuff is out of my system and I can give her my blood? For the record she knows that I smoke but right now she is too embarrassed to ask the doctor.