Word alterations

Is it common to say-
a *giggle* of girls meaning a group of girls giggling?

and

He is a workaholic:he *averages* twelve hours working in the office?

Is *average* commonly used that way

thanks

I've not heard that collective noun used for girls. There's no issuing authority for such though; if they get into common use they get accepted. I'd have thought that one stood a chance of a long and healthy life. Roald Dahl used a gigglehouse of girls in one of his children's stories.

Averages is commonly used that way in the UK.