What are some great part-time employment options for retired nurses?

Does she really want to work in health care? Maybe she has had enough. Maybe a book store, hardware, fabric? Library? So many options that don't have to be health care related.

The VA might be interested, especially since she was in the AF.   Even if she's not able to provide nursing at a veteran's home, her skills would be cherished in making assessments of a veteran's status.    She might be interested in being a visitor; I learned when registering my father that some people volunteered just to visit Veterans; a nurse volunteer would be a real bonus.
She might also be able to have one day "nurse checkups" at senior facilities.   I don't know though if these are volunteer or paid opportunities.  

She might check out local hospitals; my understanding is that b/c the Covid crisis diminishing at one point, many medical personnel were laid off; raises were either not given or minimal for those who did stay.    Now that another crisis is on the horizon, ER's may need additional help.

Employment is likely less likely than actual volunteer work, which many would absolutely love her to do in any of the places already mentioned. I do think they are speaking of hiring retired medical personnel for vaccination in the future, but that will likely be well into 2021, and no clear plans until the is Covid-19 vaccine. I kept my license active for a long long time, so much a part of RN was a part of ME and who I am. Finally gave it up and was shocked to get a certificate of thanks from the State along with the ease with which I could reinstate my license. I had always thought that an old RN such as myself (78) would be a bit much of a liability for hiring on given how quickly medicine moves. I do wonder about phone nurses though, such as Kaiser uses. Because it is pretty simple when to tell folks to go for help.

Hospice is always looking for Volunteers.
The Hospice that I Volunteer for has quite a few retired nurses that do anything from visiting with patients in homes or facilities (not in facilities right now though) they are also in the In Patient Units helping the CNA's and Nurses.
Local Health Departments have clinics that they might want volunteers to help with.
If she wants to go back to work Hospice also might be a good option. There are office jobs where phones are answered and calls are either people wanting to ask about Hospice or they are Hospice patients that are in crisis and the calls are then fielded to the nurses on call. Phones are manned 24/7.

I have a friend who’s a retired RN in her late 70’s, she works part time at vaccination clinics. Loves the schedule being usually one day a week and the interaction with people. She’s also done some health screening clinics for low income patients