Renewal pretty much sucks for 7th Heaven
Story decisions have also been effected by the tight budget. For example, the big surprise at the end of season 10 where Mary and Sarah were both pregnant with twins couldn't be played out through season 11 because there isn't any money for more child actors. The article also details what is going to happen with Lucy's pregnancy. Ruthie is off at school in Scotland indefinitely, until there's money to pay the actress to return for an episode or two. And the contracts for the parents only require them to appear in 10 of 13 episodes... leaving the writers wondering what the hell they're going to do for three episodes.
It's sad, really. A show that lasted for ten years is essentially being treated like dirt by a network that was desperate to get ratings but obviously doesn't want to pay for them.