[Crash Ichimonji]

There happens to be an original hentai manga (multi-chaptered) that was based on the theme of the post-heroic lives of several magical girls (one even being a magical girl from the evil forces) in their late 20s to early 30s. The title was "Snow Knight Whitey (30)" and you can find it on Ex Hentai.

WARNING: THE MANGA IS ALL STRAIGHT-SHOTA.

With that disclaimer out of the way, there are I believe two actual MILFs in the group of mature women in the comic (3 if you count the adopted mother of the lead male who raised him but she never became pregnant in life). The interesting aspect was that it had flashbacks of the mature women as they were in their youth as tween and teen magical girls, full of righteous fury and energy fighting the bad guys, then panned to the present with them as housewives, clerks, mothers, etc. dealing with 'normal' struggles typical of the mature/MILF archetypes (with added humorous hentai content and their longings to don their magical uniforms once again to relive their glory days).

The part I liked in particular that wasn't porn-related was how the manga tries to act like it's an epilogue of an actual magical girl series. Almost makes it a frame story to that end.