perhaps counseling might help both you and your daughter. this would likely be true for the loss of any spouse/parent, but may be especially true in this particular case.
to your daughter, i found with mine the best way to handle her was to not give her Advice unless asked for it, to not give her a Choice in certain matters, and to not Explain my decisions (ACE). She didn't' always like it, but she could count on it and it helped me to act like a parent even when I wasn't in the mood or mind-frame to do so.
In this case, and it seems like you are doing it anyways, if you want a driver's license then this is how it's going to happen. Period.
Good luck to you. When my wife dies I'll feel guilty too, but I can't wait to be free-- finally ******* free (FFF). And, though she likely does not feel it or realize it now, your daughter is FFF too. The goal now is that she grows into somebody that won't be looking for her father in a boyfriend/husband. That's why counseling, Alateen, and Alanon are so very, very important.