Crossword Genius

Girl at a celebration (4)

Ross

I believe the answer is:

'celebration' is the definition.
(gala is a kind of celebration)

'girl at a' is the wordplay.
'girl' becomes 'gal' ('gal' can be a synonym of 'girl'**).
'at' means one lot of letters go next to another.
'gal'+'a'='GALA'

(Other definitions for gala that I've seen before include "Prod with the elbow", "Fête", "Sports meeting", "A show of charity", "Festive entertainment".)

I've seen this clue in Mirror.