Underneath her coat, the 13th Doctor wears a short-sleeved stripy shirt over a long-sleeved white shirt.
I had many ideas for how to make the white sleeves attach to the shirts themselves, none of which worked when put into practice.
As a result, the white sleeves are not attached, they can be removed so the shirts can be worn as short-sleeved shirts.
All she needs now is a sonic and a TARDIS, and she’s ready to explore the universe!
Anyways, see ya!