I played the Pancakes for a while in one of my saves. The got different outfits, hairstyles and Bob started to work out. A lot.
http://i.imgur.com/SRGwMRm.jpgI worked on their relationship as it was really bad and joined them in one bedroom. They were doing really well. I rotated to another family and when I came back to them, because I thought they should have kids, their relationship was quite bad again. It needed much improvement before I got them in the same bed again. I thought this was interesting, because apparently some traits do really have an impact with Bob being a slob and Eliza a neat freak.
Their first child, Peter, turned out quite well. As a matter of fact he is all grown up now, doing well in the astronaut career and is dating one of my sims.
http://i.imgur.com/cZ7jVjn.jpgTheir daughter Wendy unfortunately did need some help with her chin, which was pretty much non-existant, when she grew up to be a teenager. Here she is as a child though.
http://i.imgur.com/wNzbqAi.jpg