Awww, congratulations ?. It’s such a lovely time, especially the first grandchild. Are you going to be with her at the birth? Husband/ partner? It’s perfectly fine and normal to be nervous, but no matter how it all goes, it will have been seen before. Hundreds of times.
I used to worry about waters going in the shops. They never did for me, in fact with all my four...the waters were broken!
Just take each day as it comes, perhaps don’t venture too far away from home / hospital, and make sure you and her partner? are easily contactable.
All the best and hope it goes well for you. Do come back and tell us.