Curious how other non-profits mitigate this never-ending battle? We receive two first names in the first name field quite a bit when contacts are making a donation. For example: First Name: "John & Jenny", "John and Jenny".
I've spoken to our fundraiser platform to see if we can implement some sort of validation on those fields but it feels like I'm the only one complaining about this.
We consider it dirty data and separate it on our regular data cleaning schedule (monthly). We have reports to try to detect it. Separation allows each contact to evolve separately and other family members to come into the picture. Sometimes they even share a single email address but we separate and allow the duplicated address in that case. It's not necessarily optimal but it's a governance choice that should be made by stakeholders and then put reports and procedures in place to fix. We don't try to block (since that's not very customer friendly) but rather fix. Of course, if we're importing, we try to clean up prior to import.
--Terry