Without knowing anything (except your own clear thumbnail sketch) about you as a couple, about your mother, or about the triangular relationship that inevitably exists amongst you…
…I do have experience with the mental health challenges that elderly people face personally, and the consequences for them and their support system, of a major dislocation from the familiar, the understood, and their position in the world
Old people, and your mother is very old, are very susceptible to major mental changes in such situations, and the likelihood of a severe and acute depressive illness developing has to be taken into account, not uncommonly with psychotic symptoms: abnormal suspicion, agitation, disorientation and mental clouding. The symptoms are not always immediately obvious, but can reach a crisis quickly, requiring urgent intervention
It’s best to be aware of this likelihood in case it does actually supervene. It may not, of course, but the potential is there for you all. Also bear in mind that your own process of adaptation is likely to have it highs but also it’s lows, and that may complicate your own ability to cope with a major life change. Six to twelve months in is a fertile ground for rising tensions, and sometime for ineffective methods of coping with change, especially when matched against high expectations
Mental health resources available to elderly people in rural France are acknowledged to be grossly under-resourced, and although medical care is very good, it’s presence in some rural regions is very patchy. Your mother’s inability to speak or understand French would also pose major limitations on its usefulness to you all.
Everyone, including me, will wish you well in fulfilling your ambitions to move to France with your Mum, bit it would not do justice to your situation or your appeal not to respond frankly, which is what I have done here.
PS contact me by using the private message facility if you want, and I will answer any questions you have, or respond to your own comments on what I’ve said here.