Scootaloo, Sweetie Belle, and Apple Bloom have their "Gabby Gums" gossip column (is it more like tabloid or yellow journalism?) in which they write about various gossip concerning Ponyville and even elsewhere in Equestria.
In one edition, the CMCs write about Mr. and Mrs. Cake allegedly planning to get divorced (although it is not actually true).
Possible scenario: Scootaloo lives in Ponyville with her divorced mother. Scootaloo's older sister left Ponyville a while back with their biological father. That explains why Scootaloo looks up to Rainbow Dash as a sort of pseudo-sibling.