The mini-series marks the 60th anniversary of Doctor Who, and will see Tennant return to the role of the Doctor before Ncuti Gatwa officially takes on the role from the festive period.
In May 2022, it was announced that Finney would be joining the show as a character called Rose.
The name instantly attracted the attention of fans, who questioned if it was a reference to Rose Tyler, Billie Piper’s character who was a companion to both Christopher Eccleston and David Tennant’s Doctors.
While the nature of new Rose’s identity had been kept under wraps, many Whovians had theorised that she is the daughter of Donna and her partner Shaun (Karl Collins).
This was finally confirmed on Wednesday (30 August), in a social media post marking Finney’s birthday and confirming that Rose is Donna’s daughter.
The description reads: “When we last saw Donna, the Doctor had to wipe her memory. So the question is, what happens when Rose meets one of her mum’s oldest friends?
“It is a mystery for now, but what we do know is that just like her mother, Rose stumbles across something alien and from that point her seemingly ordinary family is never quite the same.”
In Donna’s final episodes in Doctor Who in 2009, all memories of the Doctor were wiped from her mind.
The Doctor then warned her grandfather Wilf (the late Bernard Cribbins, who was seen on set of the anniversary episodes before his death), that “if she ever remembers me her mind will burn and she will die”.
In May, trailers for the Doctor Who 60th anniversary specials, called “The Star Beast”, “Wild Blue Yonder” and “The Giggle”, arrived.
The clips gave fans a glimpse of Tate’s return as Tennant’s sidekick Donna, as well as a mysterious new character played by Neil Patrick Harris.
In a recent interview, Tennant that he wanted to play the character again before he got “too old”.
“The specifics of coming back to Doctor Who took a bit of wrangling,” he told the Radio Times. “But we were always receptive to the notion. Initially, it was a casual conversation going, ‘Wouldn’t it be fun to do a one-off?’
“Then Russell was back running the show and suddenly it could be something bigger. But there’s really no pressure. It’s a victory lap, in a way – you get to enjoy something that had meant so much to you, one last shot before you get too old to do it again.”
Doctor Who returns in November on BBC One in the UK and Disney Plus in the US.