I don't think Crystalblaze is Sparrowtail's kit since she's our sister in KTL also the other 2 siblings with gemstone and creamfrost are breezekit and foxpaw (foxpaw was snatched by a hawk) , other sibling in Bramblestar's litter in Moss-shadow
on crystalblaze on the west woods wiki it says her parents are unknown but on sparrowtails wiki it says that crystalblaze nightwhisper and milkywillow are her kits so honestly idk--
