NOT normal for "extra" items for grandparents to be on the registry.
Fun story...My MIL's friends (8 ladies) threw her a suprise grandma shower (it's her first grandchild) she didn't create a registry obviously, but they did get her a super cute diaper bag, a grandma tshirt, a grandma's sippy cup that is actually a wine glass, a rock n play, some books to read to baby, a really cute baby blanket, some bibs that say "I love Grandma", some baby toys and a gift certificate for a grandma and daughter (in law) mani-pedi! It was really sweet!