May I write a note as if I were your daughter?
Dear Mum,
I'm sorry he's not staying over with you. I hadn't quite realised what trouble I'd be putting you to, hauling all your stuff over to our place. So I elt really bad when you pointed it out, and asked a friend to babysit him.
As you'll remember, going into labour is quite a traumatic thing and I want to know my wee boy is safe and happy, when I am helpless and away. Does that make sense?
So having him in his own bed, with its own smells and comforts, is essential for my well-being as well as his.
I've never gone along with co-sleeping either, even with us, so not with a grandma who isn't too well either, for everyone's sake. It's really nothing personal in that sense, just not right for my peace of mind.
I am very precious about my boy, I know that. He's only three and so very vulnerable. Maybe when I have two to look after, I'll let go a little but children are surrounded by so many dangers and I'm sure you were as fearful for me when I was tiny. So much can go wrong, can't it?
I hope you will try to understand how I feel, especially at this time with all my protective hormones raging.
I don't want to make things any more difficult than they already are and with your health problems, you've enough to cope with.
I love you Mum
Your dear daughter.