After running away from owners who treated her and her brother poorly, both cats spent many moons alone, living under poverty, until they stumbled upon clan land.
They were seen by the leader of Lunarclan, and the leader was surprisingly happy to accept them as apprentices to the clan. The duo was mocked for their kittypet past--especially Cloudtail because of her small body.
She proved to be a great warrior though, stunning her clanmates. As of now, she is skilled in battle and her brother is a medicine cat apprentice.
(inspired by Avian's "Crescent'face" drawing)
(Edit - Ugh omg when I made this, I literally had no knowledge whatsoever upon Warrior Cats lol. I only made this because I loved Avian's drawings and wanted to make something similar. I asked my friend who knew some lore of WC, but other than that I literally had no idea what WC was haha)