She lives in LA (4)
I believe the answer is:
lisa
'she' is the definition.
'lives in la' is the wordplay.
'lives' becomes 'is' ('be' can be a synonym of 'live').
'in' indicates putting letters inside.
'is' inserted within 'la' is 'LISA'.
(Other definitions for lisa that I've seen before include "Girl" , "Mona . . . ., famous painting by Leonardo da Vinci" , "Mona ..., also called La Gioconda" , "Most intelligent of Marge Simpson's children" , "Leonardo da Vinci painted the 'Mona ....'" .)