Hi Bonbon 8888
Congrats on being a first-time Nana!
I know all babies are precious to parents, but your grandson is particularly so to your Dil. She is probably worried he will pick up some germs and so has a strong maternal urge to protect him.
Maybe you can wait for her to offer you to hold the baby, which I'm sure, in time she will. Just try to be patient.
She may appreciate a helping hand with some of the house chores or preparation of a meal, leaving her to concentrate on baby care.
I must say baby is doing well with his sleep pattern, seven hours at eight weeks old! My Dil is up breast feeding two or three times at night, and baby is over one year old, but then all babies are different and wonderful in their own way.
I would just try to be as supportive as possible and go with the flow.
In time things will improve, as your Dil becomes more confident and secure in being a first time Mum
Good luck and enjoy the days ahead!