If it had been two males arguing, I suspect that the FAs would not have taken
any chances and stopped it right away.

Perhaps there is a general feeling that 2 females involved in a catfight poses
less danger to the plane and passengers and is see just as entertainment (or annoyance).

I hope that Virgin will install a large vat of Jello in the belly of its
A340-600s. Whenever such a catfight starts, throw the 2 (or more) females into
the large vat of Jello and then have cameras retransmit the fight live to
satellite TV networks all over the world. Consider the revenus Virgin could
derive from this :-) :-)