Bless her bones. I think Mrs. Thinker and I have the same challenge with in-laws and I completely understand her tears.
For you to see/know this about her is an intimacy. Just speculating but based on a lot of experience in this very arena (!), that woman believed she was protecting you from this. She probably struggled with not wanting to be in the position of making you choose. And being good enough. And presenting children to your parents who are good enough. And belonging. ALL VERY TENDER AREAS FOR A WOMAN.
I'm so happy for her that you can see this. Now she has a partner
Me45 H46 T25 M22 S21 & 19 D13 Separated and filed 8/08 Moved home 11/08