17 is definitely very young
And you have a lot of bravado at that age
Just saying
A lot of us would do / have done things at 17 that looking back we would view in a different way
However it was her decision and that of her father
It doesn't mean anyone needs to feel comfy about it though
Everyone has different lines
For eg the 14yo where its known the dad was sexually abusive ? art or not art, some poeple have a line
Or the image of brooke shields in a playboy spinoff, aged 12 or something, recently displayed in london I think? Again, some poeple had that line
The line of feeling uncomfortable about a dad painting his daughter in this pose at 17 is hardly crazed prurience of victorian standards
And of course the image needs to be taken in the context of the society in which it was made > and naked woman with legs apart didn't mean much different then to what it does now, to most people, even with the slightly peculiar insistence that it was a different time so this image and the relationship between artist and sitter is unremarkable.