Good evening! I know this was posted more than 5 years ago, but I'm hoping there's still a chance!
I knew Mrs. Maxwell very well - and I can confidently say that she did not pass away in Brazil as the other poster suggested. She went to Brazil with her husband in the 1930's and contracted a disease that affected her eye sight. She had to return to the United States, and he stayed behind in Brazil for several years. They never reconciled or "got back together" when he returned to the United States. She never remarried or had children.
She lived until almost 100 years old and was like a grandmother to me. My dad grew up next door to her on Glen Lily Road in Kentucky and took care of her lawn, etc during his adolescence. When he married my mom right out of high school, they lived with Mrs. Maxwell for several years, and that's the first house I lived in when I was born 2 years later. She was such a kind woman with a big heart, and I loved her dearly. She was an amazing musician, even more so because she was almost blind. She taught me to play piano, and when she passed away left a beautiful upright piano to me. She did not have any children or other remaining relatives, and donated almost her entire estate to charity when she passed away.
If you still have these letters, I would LOVE to see them. You may email me at hannah e lawrence at gmail dot com.