I made the mistake of assuming Elaine's age was constant throughout her entire canon (or that her canon was short enough to not make a difference). Which, when I think about it more, is pretty dumb.
Elaine starts the Lucifer series at the age of 12. This is around the same time that Lucifer promised his duel with Amenadiel for one year later. We see the duel happen about halfway through the series, which would make Elaine 13 at that point.
Near the very end of her series, Elaine mentions that it's autumn again, the same as when she'd left at the age of 12. So this implies another year had passed. But since she mentions this at the end and Amenadiel's duel was only halfway through the series, then in total two years had passed, making Elaine 14 by the end of her series.
Effective after this post, Elaine's age is adjusted to match the above. All previous interactions regarding her age still stand, and with a bit of ooc magic can hopefully be sidestepped and grudgingly put up with.
TLDR:
In
entranceway this all in all means she was around 13 or 14 when she first joined, but I'll stick with 14 because the point I took her from in her canon is closer to the end than the middle. Add one year since she's stayed in Wonderland for over a year now, so she's 15.
In
hellpointe Elaine is 15, since I took her from one year after the end of her series.
Conveniently, that makes her fifteen in both places. Ta-daaa!