I believe strongly it’s not what you send a client, but how long they keep it that is most important. If it goes on the fridge then you win.
One idea for open houses is to put out coloring sheets for the kids and crayons. While most people don’t bring kids to open houses with them you would be surprised how often they ask if they can take the coloring home. And guess where it ends up? Colored and on the fridge with your name on it.
If you are trying to appeal to younger families in your marketing the other important impact on potential clients is leaving the impression that you understand the needs of parents with small children. I always say “Perception is Reality” and this is a great marketing tool for open houses, your office or to take to meetings at client’s homes.