Kate Bosworth and Leslie Mann are about to get gritty. The actresses have signed on for the drama Goodnight Moon, a semi-autobiographical tale about two teens (AnnaSophia Robb and Juno Temple) who get caught up with street kids when they're duped into a bad scam. Mann will play the mother of one of the girls, while Bosworth has been cast as Mann's sister.Note to parents: despite its misleading title, sweet bedtime tale this most certainly is not (something tells me the cow jumping over the moon doesn't tend to carry a switchblade). However, I am excited to watch Mann branch out of husband Judd Apatow's clutches and take on something more serious. Do you think she and Bosworth make for convincing siblings?