The only thing i read was showers with Dad which is not a good thing from an outward appearance. However depending on her age, a lot of parents will take baths and showers because they are too young to bathe themselves. Most parents dont do that anymore but he's 80 years old so it would be reasonable that he would.
We will never know but using that diary is just a bad idea
Read all she wrote on those pages & either admit you're a Pedo defender
or just stop with this defence - You have read the other girls nipple
tweaking / pinching & seen all the videos.
Tip if it looks like a Duck , Walks like a Duck, Quacks like a Duck
& Behaves like a Duck there's a very Good Chance it's A Duck.