While it’s never easy to breakup with anyone — be it a friend, boyfriend, guy you’re dating, whatever — the key to your question is believing that you’re at “two different points” in your lives. It happens. And, it’s usually the main reason people give for breaking up with a boyfriend or significant other. So it’s not that bad of a reason to reevaluate your friendship. However, before you do anything hasty — like cut off all communication — take time to talk to your friend about the issues you two have been having. A girl is much more likely to be open to talking about problems than a guy your dating would be, so don’t be too nervous about giving it a try. And if this is your best friend, you owe it to her, and all those years you devoted to your friendship, to work through it before just walking away.