The house, a traditional 1940s white stucco ranch, felt just right to Nina Weinman. It was in central Los Angeles, where she and her husband wanted to live, and it was in their price range. It had a dishwasher and a garbage disposal, central heat and air-conditioning — all things lacking in the couple’s rental apartment. An especially welcome upgrade: the extra bathroom. “Our apartment only had one bathroom. That was not a lot of fun when we were potty-training our two children,” said Ms. Weinman, a prolific contributor of movie scripts to the Hallmark Channel — 30 produced so…