Her divorce is as good as done - I wouldn't let that stop you.
The important thing is less about the paperwork and more about, is she DONE?
In my case my ex cheated, I DBd and we reconciled, had several good years until he left in a blaze of MLC glory. When he filed I was DONE, there was no way I would have taken him back again and I had peace in my heart that I had done everything possible for my marriage.
My divorce took two years to be finalized but I began dating soon after he left. I was confident I didn't want him back under any circumstances and so was emotionally available for a new relationship. However, I had been dealing with my marriage problems for over 8 years at that point.
The big questions are not when her divorce is final but how long have they been separated and does she have residual feelings for him?