She lives in Birmingham, England and has an older sister named Sophie.

She was cast as Harry Potter and Ginny Weasley's youngest child and only daughter somewhere either in 2009 or early 2010 given that the production of Deathly Hallows: Parts One and Two were shot back-to-back as one film from 19 February 2009 to 12 June 2010. Her casting was first announced late in June 2011.

The first King's Cross shoot was filmed on location in May 2010. After the film had wrapped, it was decided by director David Yates that the Epilogue scene should be re-shot in December due to dissatisfying results with the first shoot. The re-shoot took place at Leavesden Studios on sound stages (opposed to reusing the real station, which made filming difficult during the previous attempt).

Based on personal photos of her, Daphne is naturally blonde and has blueish-gray (or greenish) eyes, unlike her on-screen character Lily Luna Potter who may have inherited her mother's ginger hair and brown eyes.

During the first King's Cross Epilogue shoot in May 2010, the creative team either had her hair dyed ginger or she wore a red wig, although during the re-shoot in December, it seems as though they may have not bothered (her hair in the second footage is closer to her natural blonde, or a strawberry blonde on camera, possibly due to a combination of lighting and post-production color grading).

According to her on-screen brother Will Dunn (James Sirius Potter), Daphne followed Daniel Radcliffe throughout the set and was always hugging him, even when they were not filming.