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.
Granite Bay, California is located in Placer County. Granite Bay is a suburban community with a population of 20,883. The median household income is $124,851. In Granite Bay, 63% of residents are married, and families with children reside in 38% of the households.