
Doctor Who's Season 2 finale, "The Reality War," gave fans some confusing twists surrounding Poppy, who may be the Doctor's daughter. Poppy first appeared in the Season 1 premiere, "Space Babies," as the captain of an intelligent baby farm, played by Sienna-Robyn Mavanga-Phipps. That episode was one of the first for Ncuti Gatwa's 15th Doctor and Millie Gibson's Ruby Sunday, with many crazy sci-fi antics having gone by since then. More recently, the Doctor has been traveling with Varada Sethu's Belinda Chandra, now finding themselves in conflict with another Time Lord, the Rani, who has conjured up a reality of her own.
How Was Doctor Who's Poppy Actually Created?
When the Rani got her hands on the Pantheons's God of Wishes, the baby Desiderium, she left them under the control of Conrad Clarke. The conspiracy-driven extremist used the genie baby to create Wish World in his image and in line with his beliefs (even throwing shade at J.K. Rowling in the process).
Within this new reality, the Doctor and Belinda were married with a child, Poppy, who just so happened to look exactly the same as the baby farm caption from Season 1's "Space Babies," but this time she doesn't speak.

This reality may not be the original one but it and everyone in it, including Poppy, is real, wished into existence by Conrad through Desiderium.
The Doctor explains to Belinda the "amazing" way that Poppy was created in this reality as "little scraps of memories" from each of them "came to life in a child of our own," hence why she shares a face with a familiar space baby.
This was only more shocking as, outside her creation through a wish, Poppy should be "impossible" as the Time Lords are infertile and "there can never be another Gallifreyan child" due to a genetic explosion.
While Conrad created a twisted world with backward morals and horrendous discrimination, he revealed to Ruby that he wanted to make things "nice" and gave them the family he never had to go along with that. Hence, the Doctor and Belinda were no exception, and that is how Poppy was born from them.
It's important to note that the Poppy created by wishes is seemingly not the same one who appeared in "Space Babies," with that one still out there somewhere. Instead, she simply shares her appearance with Captain Poppy as she was created from the Doctor and Belinda's memories.
Why Did Poppy Disappear in Doctor Who?

As the Doctor and the Rani fought to end the wish and change reality in their different ways, the same was true for both - Poppy would cease to exist. So, it fell to UNIT scientific genius Susan Triad to create a "zero room" that exists outside reality and would preserve those inside through the shift.
Ultimately, Belinda and Poppy hid inside the high-tech box while the Doctor successfully restored reality, and, luckily, the plan worked. That said, it still wasn't meant to be a happy family ending for the TARDIS travelers as Poppy suddenly disappeared, leaving only Ruby with memories of her.
This concept is nothing new, as when Episode 7 began and all of Doctor Who's familiar characters were consumed by the Wish World, Ruby was the only one who remembered what came before, for reasons still unclear.
In terms of why Poppy disappeared, that was never outright stated, so fans can only speculate. That said, presumably, the "zero room" wasn't as successful as initially hoped when the wish ended and reality restored itself, she was erased.
How Did The Doctor Bring Poppy Back with Regeneration?

Having been confused by Ruby that Poppy was, in fact, real in the previous reality (and after a brief cameo from Jodie Whittaker's 13th Doctor), the Doctor "punched a ton of regeneration energy into the [Time Vortex] to jolt it one degree."
The result was a new reality in which Belinda, even before meeting the Doctor, always had a daughter called Poppy who she had been trying to get home to all season before 7:30 a.m. on May 24, 2025.
Except, this Poppy was no longer the Doctor's daughter and was revealed by the Sonic Screwdriver to be "100% human," as Belinda confirmed the father was Ritchie Akingbola, her ex-boyfriend she had known since age 21.
Was Poppy the Doctor's Daughter? (It's Confusing)

Yes, she was originally created as The Doctor and Belinda Chandra's daughter with features from them both in the Wish World by Conrad Clarke. However, in the new reality that the Doctor created to resurrect Poppy, there is no indication she has any Time Lord heritage left - complete Chandra/Akingbola.
There's always a chance there will be more to the Poppy mystery, but, by all accounts, it appeared that the story closed out in Season 2 as Ncuti Gatwa and Varada Sethu departed Doctor Who, at least for now.
"The Reality War" brought the revelation that the Doctor and any other surviving Time Lords are sterile and cannot have children naturally. If Poppy isn't the Doctor's daughter, that leaves a lingering question of how he has a granddaughter, Susan (who had her record-breaking Doctor Who return in Episode 6).