Just by chance I looked at Rootsweb in case there was any query relating to Quill surname.Now I may not be related but I did have this family in my file as I had collected all Quills from Lyrecrompane, Rathea area.Knockalougha and Knocknaglogh are 2 different places but quite close together.
I was wondering if Mary was actually Johanna Mary ,as I had the same problem with an ancestor of mine.Sometimes she was called Mary and other times Johanna?
Would love to hear from you ,as I am very close to Listowel, and I may be of help to you.I assume you are in Ireland as well ,as you refer to the NLI, having done that trip myself.
If you wish look back on old postings and you will see how I am a Quill looking for my ancestors. firstname.lastname@example.org