She turns up in Northallerton (4)
I believe the answer is:
ella
'she' is the definition.
(I've seen this before)
'turns up in northallerton' is the wordplay.
'turns up' shows that the letters should be reversed in order.
'in' indicates the answer is hidden within the clue.
'alle' is hidden within 'northallerton'.
'alle' reversed gives 'ELLA'.
(Other definitions for ella that I've seen before include "Great late jazz singer . . . . Fitzgerald" , "Diminutive of Eleanor" , "Woman" , "- Wheeler Wilcox, US poet" , "- - Fitzgerald (mus.)" .)