Setting the scene: At a certain holiday park for MiL's birthday on the weekend. So me, DS, BIL, Uncle-in-law, Aunty-in-law, Cousin-in-law and MiL (I am widow, so no DH as a buffer between Mil and me)
I'm prepped and ready to be nice and friendly to MiL, as at the best of times, she irritates me. But - I'm ready to let it all wash over me - think water and ducks backs. 
She's fawning over DS (only grandchild) - taking him swimming and playing with him lots. So far so good. 
She spends mealtimes feeding him - spoon feeding him. He's 2.4. He can feed himself!
She is constantly calling his name in this high pitched, whiny voice. She wants his constant attention. Leave him alone! He's busy playing - he doesn't need to look at Grandma constantly!
Give him some space. Yes, he likes cuddles, but he also likes to play, which he can't while you are pinning him to your lap.
No - I'm not hungry, thank you. No, I don't want toast. No, I don't want cake. No I don't want biscuits. I'm not hungry
Yes, I remember where I parked the car (two days ago). And even if I didn't, what are you going to do about it? You don't know where the car is anyway!. No I don't need someone to come with me on a five minute walk. Yes, I know the way - because I am a grown up.
You are NOT my mother. You are DH and BiL's mother. You are DS's Grandmother - but you are not my mother. Stop treating me like a child!
Oh that feels so much better! 