Since you asked, I do think it is odd that your grandchildren sleep with you if you have other accommodation available for them. Also, a nine-year-old should be able to bathe or shower alone. I would worry more about lack of independence at that age than anything improper, but at age 9 I would expect a boy to be more modest than you are describing.
Free printable topographic map of Morro Bay (aka Moro Bay and Bernard's Bay) in San Luis Obispo County, CA including photos, elevation & GPS coordinates.
On the left, the Lighthouse Cam at Point Arena in southern Mendocino County, and on the right is the Lost Coast Cam in Shelter Cove. Cam caretaker: sunnyfortuna@gmail.com. The beautiful and rugged North Coast of California is home to this private weather station and its webcams.