Personally, if it were a family name I would use it without hesitating no matter how many other family members already had the name. However, if it was just a random name that I liked I would try to avoid using the name. 1 of my sister in laws chose a name for her DD that I really liked. Since it's not a family name (for either one of us) I wouldn't use it if I have a girl. But there's no reason or rule that says you can't. This is more about personal preferences than anything else.
