The BBC's been producing shorts on YouTube called "Doctor Who: Lockdown", which are written and produced in the content creators' own homes and intended to entertain while asking for donations to COVID-19 relief funds. An example is "Pompadour", written by Steven Moffat and performed by Sophia Myles - I will warn you to get the Kleenex before you hit 'Play'. There aren't many, but most are concerning some of the most popular episodes of the past fifteen years.
The one that broke my writer's bubble is "The Shadow in the Mirror". You probably can figure out exactly what it's about from the title. TSinM is written by Paul Cornell, who wrote "Human Nature"/"Family of Blood" and "Father's Day" as well as the novel HN/FoB was based on, Human Nature. The video reveals the fate of Daughter of Mine, trapped in every mirror by the Tenth Doctor.
That sound you just heard was a headcanon misfiring.
I wrote her fate, a long time ago. It's been a part of my imagination for over five years now: the fall of the Doctor's footsteps (and later, bootsteps) as he approaches the mirror every year, the angry eyes watching from a shadowed corner, the string of the red balloon clutched tightly in a tiny hand forever, and what she saw that finally made her think. I can't describe how it felt to watch a different reality settle into place. Ah well. It's happened before (though not to a character or story that I've loved this much), and it'll happen again.
I will say this, though, because this is my journal and I can say what I want here. To Mr. Paul Cornell, who I have actually met and talked to about DW and writing: I've adored your work ever since I first saw "Father's Day". HN/FOB is my favorite DW episode, and the original novel is stunning. Also, that Third Doctor comic you did with Christopher Jones - I totally did not see that coming. I've always felt that Daughter of Mine deserved some closure, that the Doctor felt more responsibility for her than for the other Family members, and I think it's wonderful that you created this short piece to address that. However, there's something you need to know: Mine was better.