She’s retired and we’re fully sponsoring her trip here. She had a letter stating all of those facts for both interview at the embassy and CBP.
I know every case is different, but I don’t see how it is an issue, especially if she may not come back for a few years after leaving the US. The purpose of the visit was clearly stated and no questions asked. I appreciate that other people concerned about it, but it doesn’t really answer the question regarding ESL classes.