I only a had like two sims born in game, but both of them were lucky to inherit their parents' good features :D What I noticed is to have good looking offspring, the parents shouldn't have overtly feminine or overtly masculine features, because a child of any gender could inherit those. Thus, a daughter could inherit her father's jawline, or a son could inherit his mom's soft face shape, which just looks off most of the time. Especially with Don, I could imagine that his daughter's aren't very good looking in case they inherit his facial features. You just have to be lucky enough. I have a family I created myself, but used the cas genetics feature for the twin daughters, and I had to reroll so many times until they didn't look like the female version of their father and more like their mother, because the former just looked really weird :D
