Based on math and porn law, the minimum age to be a porno MILF should be 36
Given that porn can't sexualize anyone under 18, she would have had to be at least 18 when she conceived her first child.
Since MILFs in porn are generally "my friend's mom" or something generationally similar, ie the MILF is defined as such by someone the age of her child, said child and their peers must be at least 18 as well.
Therefore, the minimum age for a MILF character in a porn, legally and mathematically, should be 36
If the kids make an appearance in the porno, they would have to be 18+. He does specifically point out porno milfs. Although I suppose the kids could just be implied in the event of a porn.
Of course it's company policy, in the event of a dildo, to never imply ownership of the dildo. We have to use the indefinite article a dildo, never your dildo
I think their logic is more that one of the big archetypal MILFs is "your friend's hot mom"
Your friend is probably about the same age as you, so if you're old enough to appear in a porn, your friend is probably is too (and has to be if they appear in the porn at all, even in a non-sexual role)
And the mother would have had to have had your friend at 18 because they want to avoid implying anything about a minor having sex (I don't know if that last part would actually hold any water, that seems like a bit of a stretch)