She'll be back in January (3)
I believe the answer is:
una
'she'll' is the definition.
I can't judge whether this definition defines the answer.
'back in january' is the wordplay.
'back' shows that the letters should be reversed in order.
'in' says the answer is hidden in the clue.
'anu' can be found hidden inside 'january'.
'anu' back-to-front is 'UNA'.
'be' acts as a link.
Can you help me to learn more?
(Other definitions for una that I've seen before include "- - Stubbs, comedy actress" , "Girl's name; indefinite article (f. Italian)" , "- Stubbs, Eng. actress" , "of satellite with no sides" , "Girl" .)