Both my difficult children will tell you that this mother certainly didn't "let it roll off her back". And I never ignored it. Punishment for that type of behavior was always major, and swift. No excuses.
Mine are both adults now and still wouldn't dare treat me that way, even during a meltdown.
Just because your child has a mental illness doesn't give them free reign to treat you like garbage. Respect has to be taught.
Hugs