I realise it is down to personal taste, and this is my taste. There is a lot of conjecture that mature ladies aren't as sexy as young ladies - what a crock of BS!
You only need to look at the two sisters in Heart http://www.heart-music.com/, both Ann and Nancy are mature, sexy ladies.
#Doro, the German rock goddess, and former lead singer for the group #Warlock https://en.wikipedia.org/wiki/Warlock_(band) is another example of a beautiful, mature lady
I can think of many mature actresses who I consider to be very attractive, but there again it is down to taste.