Can you alter the spelling slightly?
Like using a c instead of a K?
I'd have a small chat with your friend if they are close friends and are likely to spend a great deal of time together and tell her that the name she has chosen is also your chosen name as it is a family name. Explain the family connection and I would gently tell her that you will also be using the name if your child is the same gender.

I was mortified when a friend called her new born daughter the name we gave our dog and with the exact same spelling. Not because I was Oh you can't do that but shocked as she knew our dog had the same name.....not sure I could do that personaly naming a child after an animal but saying that she really liked the name and adored the spelling. As long as she's happy thats the key I guess.