It doesn't matter if you're blood related or not, family is family.

Headcanon:

The events of Season 8-9 (With the exception of The Washouts and Best Gift Ever) and Rainbow Roadtrip are not canon.

Barley and Pickle Barrel are the children of Sunshower Raindrops and Rainbow Blaze.

Scootaloo gets adopted get Bow Hothoof and Windy Whistles after her original parents and two aunts pass away.

Note: Yes, I know that Rainbow Flash (AKA Rainbow Dash G3) is an earth pony, but don't worry, Twilight gave her a special magical spell that allows her to walk on the clouds.

Also, Rainbow's line is based on this: https://youtu.be/weclhCRIt6k?si=exg5pQgLnNFyMpLR