imho, if you feel she expects something in return you can a) thank her and take a chance that she won't give you anything else. b) make some potholders- really quick and easy or of those dish towels that have fabric loops to hang them from or oven mitts, c) take her out for lunch once a year and invite her to dinner once a year. tell her you're pleased with her company.
other than being kind and thankful, i don't think you owe anything.