My aunt is 84 years old and I get a lot of information from her. Some days I can't get her to
stop talking and other days I need to call out a name and see if she remembers. Example: Her mother
had a sister named Harriett and she never said anything about her and one day Denise sent me a list from the 1870 census and I gave the names to my aunt. She then told me this aunt had a son named Athur. In short just take notes of everything your 85 year old say and always let her
know when you find some new information. Good luck with your search.