Redpaw

Mother : Dovewing (adopted), Squirrelstar (flight)

Father : Tigerstar (heart) (adopted), The impostor (Ashfur)

Sister : Sprucepaw, Lightleap (adopted), Pouncestep (adopted), Rowankit (adopted)

Brothers : Shadowsight (adopted), Birchfeather (adopted)

Half-sisters : Sparkpelt, Hollyleaf (adopted), Dandelionkit

Half-brothers : Alderheart, Jayfeather (adopted), Lionblaze (adopted), Juniperkit

Well, this is just a personal headcanon, which will last until we know the identity of Redpaw and Sprucepaw's parents (and if we don't know them, it will stay in my head). In an old AU, which you can find here:

I imagined that the Impostor and Squirrelflight had kits.

In this headcanon, Red and Spruce are therefore the kits of the impostor and Squirrelfight, who realized she was pregnant during TBC. She was terrified to realize she was expecting Ashfur's kits, and hid it, remaining in denial about her pregnancy. Then after TBC, it was harder and harder to be in denial, but she still said nothing while Bramblestar was weakening and no longer wanted to be leader. Thunderclan was really weakened by Ashfur, losing Bramblestar would weaken them even more and she couldn't see herself joining the nursery and giving up her deputy position, leaving the place free to a young inexperienced leader. She already put her personal thoughts before The Three, and didn't want to weaken the clan again by putting her life before the clan.

So she told Bramblestar about it, who refused to raise Ashfur's kits, which caused an argument between them because he was a real a**hole to her about it. But they agreed that she couldn't go to the nursery and had to become leader in his place (Squirrel out of duty to her clan, Bramble just because he didn't want those kits). So they told Alderheart and Jayfeather, and all four decided that Squirrel would give birth in secret (Leafpool vibe), and that those kits should be hidden. They talked about it with Tigerstar, Dovewing, Puddleshine and Shadowsight, who agreed to raise these kits in their clan while hiding the truth from them (Bluestar/Oakheart vibe this time). So Dovewing breastfed them at the same time as Rowankit and Birchkit. Dove and Tiger loved them like their kits, Tawnypelt always held an important place in their lives, considering them to be like Bramble's kits and considering them as her nephew and niece, and Shadowsight was an ultra-protective big brother towards them because he felt responsible for everything that happened with Ashfur. Of course, they would end up finding out who they are and there would be drama.

Yes, there are probably a billion inconsistent things in this headcanon (especially in terms of timelines), but I don't care.