maybe there's a ms paint in every session, like there is a jack and a queen and king and such in every one? if that's the case it's more likely that our ms paint is from the troll session, i think

No, she’s from the Beta kids’ session. Andrew Hussie rescued her after her exile and brought her through the fifth wall just like he did with Slick. This is where they met and she traveled with Slick to the Alpha kids’ session.