If I'm not mistaken, Myriam's age was established early on as being mid-30s. Idk why you're making her 40.
As far as the MILF title goes, as it was established by the porn industry in the late 70s-early80s (I lived through it so, as it's not gospel for some, this is referential), a MILF was initially, any woman in her early 30s onward, that had borne at least one child. It was a category established because many older female performers had stopped doing movies for a 3-5 year period, then decided to do porn again. Since they were too old to do the teeny thing and the hot girlfriend themes (plus many of them had post pregnancy bellies), they created the MILF genre for the fans of those women while creating a new niche in which to make money.
As usual, over time definitions of terms and ideas get convoluted by a small group of people that wants those terms/ideas to apply to them but That is what porn initially defined what a MILF was.
