It is common among the mothers that I know to go away on 'girly' holidays without their children.
I don't have an issue with it as in most of the cases the children are left with their dads and well looked after. Apart from one boy I know who has never been abroad and his mum leaves him 2+ times a year to go to the Caribbean/America without him. She will also leave him with anyone that will have him but that's another thread altogether.
Just wondering when it became a thing? It's not something my own mother or friends mothers did when we were growing up. Not something I could imagine doing myself either although my children are very small so who knows I may change my view when they are older and more independent.