Your thoughtful question includes good insights and understanding. You have obviously thought through these dynamics and your rational mind sees the situation clearly. But the emotional part is ruminating about her past.
The long and the short of it is that her past – specifically the unsatisfying nature of it – is exactly what has drawn her to you. The men in her past were incomplete partners because of their emotional unavailability. This dissatisfaction has caused her to make a more evolved choice — you. Your history is what is attractive to her. She wants someone who has consistency and dependability and can show up. On your side of the coin the chances are you wanted someone with more life experience because your approach to partnership was equally dissatisfying. You have each found the other because of the evolution from past life experiences. What I am trying to say is that both of your paths have led you to find each other. Celebrate this trajectory. When couples evolve together they heal the past together. My guess is this is what is happening here.