No they don't have any kits.
You may think that they did have Jaykit, Hollykit, and Lionkit but those are actually Crowfeather and Leafpool's kits. Squirrelflight covered for Leafpool and took the kits.
Squirrelflight is not infertile. She and Bramblestar have kits together in the Warrior Cats series.
No, Squirrelflight is infertile. She cant have kits due to a past injury; during Eclipse (book 4 in Power of Three) when Thunderclan fought Windclan, she suffered a massive gash to the stomach which, in turn, made it impossible for her to have kits.
YES. in one of the books, Ashfur tries to kill the Three but Squirrelflight says that they aren't really her kits. Later, the Three unravel the web of mysteries and find out who their true parents are.
I think you mean Squirrelflight, since after Last Hope events Brambleclaw/star and Squirrelflight has gotten back together. Bramblestar promoted her to deputy and they became mates again. So it is possible they could have kits if there is a series 5 of Warrior cats
No, Squirrelflight is not infertile. She has had kits in the past and is able to have more kits in the future if she chooses to.
Squirrelflight was foster mother to Jayfeather, Lionblaze, and Hollyleaf, but as revealed in Sunrise, they are actually the kits of Leafpool and Crowfeather. I suppose Squirrelflight is barren because she had been mates with Brambleclaw for so long and still doesn't have kits. But since they are not mates anymore, Squirrelflight probably won't have any kits.
Brambleclaw is Squirrelflight's true love.
No, they did not. Squirrelflight was their "foster" mother. Lionblaze, Hollyleaf and Jayfeather's real parents are Crwfeather and Leafpool. So Brambleclaw and Squirrelflight never had any kits.
First Stormpelt likes Squirrelflight but she doesn't know so nothing happens. Then Brambleclaw crushes on her so they become mates but no kits. They break up and then Ashfur is mates with her. Ashfur finds a secret he wasen't supposed to find and Hollyleaf kills him. That is all I know
Brambleclaw thought the kits were his because Squirrelflight passed them off as his to protect their true parentage, which was revealed later to be Leafpool and Crowfeather's kits. Squirrelflight did this to protect her sister, Leafpool, who had broken the warrior code by falling in love with Crowfeather.
Brambleclaw has no kits biologically, since it has been revealed that Squirrelflight did not bear him kits; instead, the kits were her sister Leafpool's. However, his adopted kits (the aforementioned kits) would be Jayfeather, Lionblaze, and Hollyleaf (presumed deceased).
Sandstorm's kits are Squirrelkit (Squirrelflight), and Leafkit (Leafpool).