I decided to try one family where they only have one child. The first generation, I didn't buy any upgrades, only basic food (the 20 coin one) and medicine as needed. No frills at all. I ended up with about $16,000 when the first sweet couple passed away together.

I decided to only purchase one room (bedroom) and one kitchen upgrade, plus a bed that was on sale, in the second generation. After less than 24 hours, I'm up to almost $22,000.