Costume trainee

To date^[update], Nikki Lightfoot and Frances Morris have been the only credited costume trainees for Doctor Who. Maudie Whitehead received the credit for An Adventure in Space and Time.

Story	Costume trainee
An Adventure in Space and Time	Maudie Whitehead
Amy's Choice	Nikki Lightfoot
The Big Bang	Nikki Lightfoot
Can You Hear Me?	Ashleigh Muza
Cold Blood	Nikki Lightfoot
Eve of the Daleks	Yiwen Lin
Fugitive of the Judoon	Ashleigh Muza
The Giggle	Lizzie Doody
The God Complex	Frances Morris
The Halloween Apocalypse	Yiwen Lin
The Hungry Earth	Nikki Lightfoot
Legend of the Sea Devils	Yiwen Lin
The Lodger	Nikki Lightfoot
Nikola Tesla's Night of Terror	Ashleigh Muza
Once, Upon Time	Yiwen Lin
The Pandorica Opens	Nikki Lightfoot
The Power of the Doctor	Yiwen Lin
Revolution of the Daleks	Ashleigh Muza
The Star Beast	Lizzie Doody
Survivors of the Flux	Yiwen Lin
The Timeless Children	Ashleigh Muza
The Vanquishers	Yiwen Lin
Village of the Angels	Yiwen Lin
War of the Sontarans	Yiwen Lin
Wild Blue Yonder	Lizzie Doody