This is an incredibly important aspect of a healthy relationship. Pointing out mistakes and trying to work on them is normal, but attempting to change the person according to your ideals and beliefs is not.
Your friends are wholeheartedly happy for you.
If you see that your friends seemed to be wary of your exes, but they are extremely happy for you when they see you with your current girlfriend, then they must feel how good of a match you two are. People can sense when the couple truly has chemistry, understanding, respect, and the truest form of love.
You can honestly talk to her about everything in the world. When you are feeling worried, anxious, or nervous about something, just like when you are feeling happy and excited, your first thought is to confide in your partner. This is what partners are for – they are supposed to lift each other up, without judging. You should be comfortable telling your girlfriend everything in the world, and knowing that she will be okay with the weirdest stuff.