And the personal abuse continues because you cannot make an argument.
OP has the right to live her own happy life and not shunt her loving son out of that normal, happy life. Babies take priority for their own parents, and to a point for others - but no. You cannot ask someone to upset, avoid or distance themselves from their own son - who let's be clear here has a disability - in order to favour you because you want them to do something nonsensical like make little to no noise in their own home after 7pm.
Just, no.
OP is already favouring the daughter and the grandchild and putting their needs above her own and her son's by allowing them very kindly to live in her home. It is actually nonsensical to expect people to creep around after 7pm in their own home and I can't believe the hysteria around this on this thread, the baby's development will be just fine 🙄. Babies are not rulers, kings and masters, nobody is smoking crack or letting an angry dog be in the room, the child is in zero danger and having to tolerate a little noise is absolutely totally and completely normal, and mother and baby will have to learn to live with it.
So, no. OP cannot live under her daughter's rule and MUST NOT allow her life to be disrupted like this. It is her home, this is a nothing thing, she simply wants to live a normal life in her own home and continue a happy relationship with her son, and nobody is being unfair to the daughter. Her daughter is being entitled and demanding.
If her daughter can't accomodate having to parent her own baby around normal, standard human behaviour then she can always leave. I would imagine, as I said, she'd find it problematic trying to enforce silence after 7pm anywhere else, she'd be in for a sad surprise.
So, no. OP is fine, son is fine, she can ask him to keep it down and if he can, great, and if he can't (it's not won't it's can't for the anti disabled people on the thread) so be it.
Their life is fine, daughter is receiving an enormous favour and must simply accept that real life is not people creeping around in their homes after 7pm because you demand it, for any reason.
OP is doing daughter and grandchild a huge and enormous favour, already favouring her, has a right to a normal life which includes more than just one child's wants, and has a right to see her son and include his needs in her life. She and the son are doing nothing wrong, it's just life.
Hope you're doing ok OP the nonsense on this thread has been pretty astounding tbh. Just keep on keeping on :)