'Bravo' to mother - she's a queen! (3)
I believe the answer is:
mab
'she's a queen' is the definition.
I can't tell whether this definition defines the answer.
'bravo to mother' is the wordplay.
'bravo' becomes 'b' (phonetic alphabet: alpha, bravo, charlie etc.).
'to' says to put letters next to each other (I've seen this in other clues).
'mother' becomes 'ma' (ma can mean mother).
'b' after 'ma' is 'MAB'.
Can you help me to learn more?
(Another definition for mab that I've seen is " Queen--, fairy mentioned in Romeo and Juliet".)