What if Celestia after the Changeling invasion finds in her bedroom a changeling foal no more than a day old. Lets say he finds some cake just laying around and she catches him or her eating it. She decided to adopt it as her child would that not be awesome or very exciting!

2239189 Quite.

I just read a story like that with Cadance, sadly it's on hiatus. Maybe someone can write another one for Celestia?

There hasn't been much stories about Celestia being extremely motherly to Spike.

2239525 Oh yes a Celestia version Love is Blind. I forgot about that story. This needs to be done!

2239189 Then Spike would have some sort of brother....

2245658 Yes he would.