A chapter book (YA or children’s) about a cat who lived 100 years in a house.
The book tells about all the people that lived in the house with the cat.
The book was (we think) written in the 1940s or 1950s.
The book or cat had an old-fashioned name.
Try The Ghost of Opalina, 1967, Peggy Bacon.
https://www.goodreads.com/book/show/566890.The_Ghost_of_Opalina?from_search=true&from_srp=true&qid=tFSQqjup0K&rank=1