I think part of the difficulty is that Granny does not generally deal with children - and is not sure how to treat/respond to them.
Sarcasm does not work the same with kiddies.
I'm not too good with toddlers/kids, as I'm never round them a lot. Its a case of hello little person....
help what do I say next... 'Yes thats nice'... help..., 'and what's the picture of?'... where's your ******* mother... 'Oh it's me' ... how the hell am I supposed to know that... '- how nice, silly of me not to know'. 'Ah'... what does wibble dibble soflabub mean...
Babies - don't even go there
You do see Granny in ER once you have read the other books, and read ER again.
But I do prefer Wyrd Sisters.