Cool meaning a positive adjective, and renn meaning rennesaince. Mary will be acting in this year's Maryland Rennesaince Festival. It's an anual event that we usually attend as visitors. It's set back in the time of King Henry VIII, and there is a lot of fun stuff to do. There are several stages where they act out plays, there's jousting (yes, real jousting) and lots of other fun stuff.
Mary's character is a wool shearer/spinner for a wealthy merchant. Her costume and props are all correct for the time period, and she must speak with a cockney accent (which she has been practicing ad nauseum) when entertaining patrons of the festival. She's having a lot of fun with it
Paul