Doodledog
Well, that's a point of view; but personally I see teaching children to live and let live, and to be tolerant of people as a good thing. Not to be a doormat, which there is absolutely no evidence for thinking is true of the OP, but to be understanding of others.
I don't think that being emotionally needy is necessarily 'toxic'. Irritating, maybe, but toxicity can take worse forms than wanting to be thanked for small favours, and with a mature attitude to it the OP can teach her child to deal with it kindly, and to save drawing lines in the sand for when the situation requires it.
I think that far from projecting 'unwavering deference', showing children that good people can sometimes be annoying is a good lesson. Clinical narcissists lack 'object constancy' (the ability to see that people are not 'all good' or 'all bad', and that sometimes we feel anger towards people we love), and whereas it must in some ways be simpler to make life exactly as we want it by refusing to allow others to do anything that doesn't make us feel gratified, I think that part of bringing up emotionally healthy children is to teach them that things are not always so simple. Part of loving someone or just being able to rub along with people on more than a superficial level) involves accepting foibles and finding a way to keep our own integrity without trying to walk all over others.
If only live and let live were applied across the board. This young woman asking for advice here is not being told to live and let live. She is being told to accept improper treatment, even though she is already making time weekly to see her MIL. The hypocrisy is pretty clear. Why can the OP not be allowed to live without unnecessary poor treatment? It is absolutely unwavering deference being pushed because the same leeway is not applied both ways.
Being tolerant of people does not mean accepting objectionable treatment, and it shouldn’t be hard to see that. Tolerance should be taught with regard to differences in individuals, not with regard to poor treatment consitently directed at a person. We’re not talking about tolerance of personalities, we are specifically speaking about teaching women and children to tolerate abrasive behavior specifically directed toward them. The general rule doesn’t apply in the OP’s case.
Loving someone and spending excessive time around them are not one in the same. Love can be present with a bit of space, and that’s important to teach children. Love isn’t and should never be defined by how much you allow a relative to mistreat you. That’s a dangerous and unhealthy concept.