This is because that sim had completed something, and it gave them an extra trait so to speak. I have seen this with a couple of different sims, in different game files. At the moment I can't remember what it was, but it has something to do with completing either a certain skill, or completing a certain I forget what it's called, but like when it comes to gardening once you complete the series of things, your sim will have the ability to be protected from fires, and the soul mate has the ability to comfort their partner....I hope this made sense. But I'm thinking the one your sim completed had something to do with the money one.