AFAICT, the underlying question is "can older characters have sex appeal".
We know 2 things: People don't stop having sex at 25, and people in retirement homes still find ways to get naughty with each other.
=> The answer should very clearly be yes.
The difference is, a character with Venus Blessing, whatever their age, is perceived as more attractive than normal.
So, how does age enter the fray?
Well, through additional difficulty.
If someone aged 70 is trying to seduce a 20 years old, they'll have to make a roll. This roll will probably have an increased difficulty, which Venus blessing will make easier to beat.
So, Hot Granny? All things being equal, yes 