I do not think it is dangerous.
I do think it would come as a helluva shock to see my dc on web when I didn't pt them there.
I think a wee friendly email asking to change privacy settings would be okay and remind her of your concerns and involvement.
On one hand the fact she wants to show them off is probably good. But from your pov I see that her 'ownership' of them would piss you off!
Don't just let it slide if it bugs you, talk/email/txt, try to be nice and gentle to avoid problems but say something or you'll be all pent up and cross.