For 1, yes I'd rub it off since she is 80.
My MIL is this way also she thinks it's weird I breastfeed as she formula fed all her 3. She tells me step by step what her kids were or were not doing and by what age. Like by 3month no more paci, by 1 year no more bottle, by 6mon sleeping by themselves through out the night yada yada yada. Like I give a sh*t.
Everyone can only give you their advice wanted or not based off their own experiences. I think they try to help and/or like to think or dramatize how great of a mom they were. If that makes sense.
My mom will do it too, and I know how things were when I was growing up so w/ her i'll usually set the record straight. W/ MIL or other folks I do the "mmmm" interesting thing also, cause it's not showing you agree nor is it giving them a chance to rebuttle (sp?)
Also, I noticed i'll be "that" person sometimes too and when I notice it i'll try and change the subject lol.