HAHAHAHA I’m not even joking I have so many accidental baby headcanons about every Homestuck.
Basically in a perfect world Rose and Kanaya live in a beautiful Victorian house and basically one day Kanaya finds a gurgling pink thing rolling around in her garden and she promptly freaks the fuck out because she has no idea what it is, how it got there, or what to do with it.
Rose attempts to take care of the poor baby while Kanaya is calling the authorities and summarily manages to light nearly everything on fire. No one is sure how this happened. Rose is very perturbed, because how the hell could her souse of a mother raise her from infancy when she herself can’t even get the damn thing to stop crying for one second.
Eventually they call Dave and Terezi out of sheer desperation, and amazingly enough (or not at all) Dave and Terezi are fucking great with kids. Dave takes diaper duty and Terezi makes funny faces and eats half the baby food, but they put the kid down like pros.
Dave demands he be called the Grand High Baby Wrangler and Terezi names the kid “Applesauce Justicebaby” and holds him over Rose and Kanaya’s balcony while reenacting the Circle of Life from the Lion King.