Oh, my! That "I wish I hadn't listened to you" rubs off the wrong way in most cases, especially when you hear that from someone you genuinely wanted to help with your advice.

The new approach you decided to take with her is the way it should be, even if you are talking to someone that appreciates your advice.

Sometimes, the best way to help people is to make them think about what they are facing so they can come up with solutions on their own. That's a very practical approach and it also teaches them to be responsible for the outcome of whatever decision they finally make.