The child that Clark Gable had was with Loretta Young, not Crawford, which Young acknowledged publicly in a biography that was to be published after her death. The typical reaction from the studio would have been to rush Joan to the abortionist, something Loretta refused to do. Loretta came to understand that the pressure she was put under by Gable would have been called date rape today but it caused tremendous problems between her and her daughter who thought Loretta, a devout Catholic, was a hypocrite. Loretta suffered from terrible guilt her whole life and Gable took no responsibility at all for his daughter. From all the books I've read women in general were continuously pressured to sleep with producers, directors, male actors with clout in the industry,, etc, so Joan's stepfather was undoubtedly one of many men who expected Joan to go to bed with them. Women like Bette, Loretta Young, etc were known for refusing to be pressured in order to get better roles, etc.
BTW, Myrna Loy, an actress I really admire, was a friend of Joan's and said the only time she was happy that she couldn't have children was when she saw Christina Crawford. She said Joan never complained or said anything negative about her children, though Loy thought Christina was an awful, impossible girl. Loy worked with Christina on stage and said that she had talent but simply refused to do what the director asked of her, caused problems for everyone else and therefore didn't go anywhere in the industry. Loy said that Joan loved the trappings of a movie star, something that didn't impress Loy at all - she was one of the divas of her day - but there was no greater friend and that Joan would do anything for you and give you anything she could if you were a friend of hers. She found her kind and caring. I sympathize with all of these women; it couldn't have been an easy profession for a women and it doesn't seem as though many of them had what we would consider a happy childhood.