Jill is a beautiful, thirty-year old brunette woman who showed up with Russell as his date to Evelyn Harper's
birthday party in "Springtime on a Stick".

Two and a Half Men

When Russell brings a much younger woman named Jill as his date, Evelyn is hurt by this, but her luck turns around when she and Jill connect and make love in Alan's shower (which horrifies both Alan and Charlie). Evelyn later takes Jill back to her place for more sex, leaving Charlie and Alan stuck with Russell, who's high and hallucinating off of pharmicuticals.