Stella's mom adopted Meme because Meme didn't have a mother. You...it made sense at the time. You had to be there.
I'm not saying that it didn't make sense, it's just... unsatisfactory. I don't really know to explain it. I guess you had to be there or something.
Basically, one of @Ragnarok's RPs, Twilight Academy (which I won't mention much seeing well, let's just say my primary character design for that left a lot to be desired) and one of @KJ's RPs, Super Academy (which I won't mention much as I wasn't actually in it so I don't know much about it) all had a crossover with RotMG in SA's world and thread. During which, due to player shenanigans:
Selina had been heavily enchanted, but a legally drug-dealing magical doctor with the ability to emulate Walter White along with an amalgamation of the spirits that once resided within inanimate objects (with a rather justified dislike of people jacking off) in a form of a somewhat ursine construct helped disable or mitigate some of them.
Ashley fused with her other self, went psycho for a bit, lost her child to the void, creeped a few people out and got tased by the aforementioned construct's reactive armor. As a result, she gained a third form and a second ability (brainwave manipulation) along with a psycho alternate personality.
Ashley became a pseudocouple with Conny.
Kyle was completely inactive and drifted away from everyone since @KJ was offline.
The sheer post rate inflated Cyrielle's magic charge until she had so much charge she insta-killed an entire army.
Will and Stella began getting close and eventually became a couple.
Selina may or may not have been partially seduced by her alternate universe counterpart's Luna.
Richard x Cyrielle shipping though no real result occurred.
Annie and Wheatley were created.
Izzy x Luca shipping with both of them trying to hide their feelings from one another. Which was rather successful, except pretty much every other PC noticed it.
A PC (Gerard/Gerald, can't remember which spelling) in an attempt to prepare a trap to take out an enemy army rigged an entire city full of people with explosives. This included shopping centers, prisons and schools. A rather poorly executed attempt to convince him that it was a bad idea resulted in all said explosives being detonated.
Selina got addicted to an alternate universe' vampiric Angel's venom and became infatuated with both Angels in a rather creepy, pedophilic-subtext ridden manner.
Conny got redrawn by above mentioned doctor, which, due to an overshot, made her gain the ability to very easily seduce people.
TA characters Meme and Alice Azifernia joined the party.
SA characters Lucas, Izzy, William and Stella joined the party.
In short, they barged into someone elses' thread, blew up the city it was set in, dissected the thread's corpse and wore it as a coat before proceeding to graverob all the characters.