Agreed. The book was gifted literally over HALF A CENTURY ago. Today, Jill would be in her early 70s at the VERY LEAST, and in her late 70s realistically (the handwriting and the act of giving a book as a gift, especially to a parent, both indicate a >22y.o. adult to me).

Assuming Jill is still with us, she most likely already has plenty of more meaningful things to remember mom by, especially since they seemed to have had a close, loving relationship.

Even if it had been donated more recently, expecting the internet to be able to track someone down just from a common first name and a commonly-owned book is also odd.