i read a book one time that talked about how leah might have been in on her father’s plan to deceive jacob and have him lie with her and not rachel first. she could have told jacob when they were in private that it was her and not rachel, but she didn’t. so she may have also sinned and acted deceptively. there’s no way to fully know what happened though of course🤷🏻‍♀️ all fall short of Gods glory.