With great enthusiasm, similar to mother and daughter (4,3)
I believe the answer is:
like mad
'with great enthusiasm' is the definition.
(I've seen this before)
'similar to mother and daughter' is the wordplay.
'similar to' becomes 'like' (I've seen this before).
'mother' becomes 'ma' (Ma is another word for mother or mum).
'and' says to put letters next to each other.
'daughter' becomes 'd' (genealogical abbreviation).
'like'+'ma'+'d'='LIKE MAD'
(Other definitions for like mad that I've seen before include "With great intensity, energy, or enthusiasm" , "wildly" , "With furious enthusiasm" , "Energetically" , "Furiously" .)