'Bevy', perhaps. That word applies to any collection of ladies and it has a nice alliterative ring for 'bridesmaids'...Yes, "a bevy of bridesmaids" sounds good.
I should poinnt out that 'bevy' with one 'v' is the word originally applied to quail, larks etc and has nothing to do with 'bevvy' - generally with two letters 'v' - meaning a drink. Yes, bridesmaids do sometimes have a drink or two too many, but there really is no connection!