I really wouldn't worry about "old patterns"...


IMO, she confided in him simply because a) she had nobody else to (she spent a year alone according to you) and b) he was someone she had already learned to trust.


So he was the safe choice since they've known each other so long and she didn't have a partner to lean on.


Now that you are in the picture things are entirely different, she wont need to be emotionally involved with him because you are now fulfilling that need. And as long as you keep doing so, there's absolutely no reason to worry about her needing him in any such capacity in future.