Blair Waldorf has a 16-year-old daughter in the new book, and Chuck is not confirmed as her father

I have a little early detail about the new Blair Waldorf book for you: Blair has a sixteen-year-old daughter.
Her daughter is almost the same age Blair was when the original Gossip Girl story began. We are going to meet Blair as the mother of a teenage girl who is entering the same Upper East Side world Blair once ruled.
The new novel is titled Blair and is being written by original Gossip Girl author Cecily von Ziegesar. It is a standalone sequel set twenty years after the original books. Blair is now in her forties and returning to New York, where she plans to work her way back to the top of Upper East Side society. The book is currently expected in summer 2027, although an exact release date has not been announced.
Is Chuck the father?
Chuck Bass has not been confirmed as the father. Blair’s daughter’s name and the identity of her father have also not been revealed.
Any theory treating Chuck as the definite answer is mixing the television ending with the book universe. On television, Blair married Chuck and they had a son named Henry. None of those events happened in the published book story.

Book Blair’s main romantic history was with Nate Archibald. She and Chuck did become involved during her college years, but their relationship never ended in marriage. Blair’s final published path had her completing Yale, preparing for Yale Law School and putting her future ahead of the old cycle with Nate. She had no confirmed husband or child when readers last saw her.
The father of her daughter could still be a familiar character, but no existing information proves it. Chuck is one possibility, not established canon.
Blair becoming a mother changes her entire position
She spent her teenage years trying to control her future while fighting anyone who tried to control her. Eleanor had plans for how Blair should behave, whom she should date and what her life should look like. Blair hated being managed, even though she constantly tried to manage everyone around her.
Now Blair is the parent.
At sixteen, Blair was competing with Serena, protecting her social position and making nearly every decision with Nate or Yale in mind. She knew how quickly a friendship could become a rivalry and how one rumour could change a person’s place at school. Her daughter is old enough to face the same pressures, and Blair knows every trick because she used them herself.
A daughter who behaves exactly like teenage Blair would be difficult enough. A daughter who has no interest in Blair’s rules could be even harder for her to understand. Blair may believe her experience gives her the perfect guide to raising a girl on the Upper East Side. Her daughter may see the same experience as proof of why Blair should stay out of her life.
There is also the Serena problem. Blair worked for every title and invitation while Serena often received attention without trying. If Blair’s daughter is naturally popular, relaxed and unwilling to compete, Blair could find herself raising someone who reminds her more of Serena than herself. Blair would then have to separate her old jealousy from her daughter’s actual life.
The daughter does not need to become “Blair 2.0” for the story to work. The stronger conflict comes from Blair realising she cannot plan another person’s adolescence, even when she knows how badly those years can go.
Why is Blair returning to New York?
The announced premise says Blair returns to New York and tries to reclaim her place in Upper East Side society. It suggests she has spent time away from the world she once ruled or has lost her position within it. Her former home and adult career have not been disclosed, and the reason behind her social comeback remains unknown.
Her book ending also makes her professional future harder to predict. Television Blair inherited her mother’s fashion company. Book Blair studied political science, pursued pre-law opportunities and entered Yale Law School. The new novel therefore begins with a very different career path.
Serena, Nate and Chuck have not been confirmed as returning characters. No screen adaptation has been announced either. Leighton Meester has read the first seven chapters, but her early access does not mean the television story will replace the book canon.
The biggest question surrounding Blair reaches beyond the identity of her daughter’s father. Blair spent her youth believing she could build the perfect life if everyone followed her plan. Raising a sixteen-year-old will show whether she learned anything from Eleanor or whether she has become an even more determined version of her mother.