My best friend and I were preg at the same time (I was 3 months ahead of her). Of course we discussed names. I told her my favorite girls name, which is Danish. She later mentioned that she remembered hearing the name somewhere, and thought she might use it. I felt silly saying, "No, that's MY name!" I used it when my daughter was born, and I bet she now thinks that I stole her name!
Kids grow into such different people that it doesn't much matter if they share the same name. I say, use it when the time comes, and just say that it has always been your favorite name.