You are 100% correct re having separate guardian table however it is a little hard to restructure database at this point. It will mean a VERY LOT of work from the ground up
1. I truly doubt it would take much time. Unless there is far more to this database then you are posting
2. I pretty much can guarantee it will save time in the long run. Trust me, I have seen this a million times before, where it becomes a band-aid on top of band-aids to do a simple task because the data is not normalized. This has already been proven. To do a simple thing like show Mother or Father, I had to demonstrate either a pretty involved Union query or build multiple subforms. You were even considering hard coding hiding columns.
So you can choose to do what you want, but you are highly unlikely to save any work IMO
.
Maybe it will never happen with your data set, but in the real world I hate to tell you there is
1 dad1 and dad2
2. mom1 and mom2
3 Mom1, Dad1, Mom2(step mom), Dad2(step dad)
4. Legal Guardian.
...
If this happens to you will have to add more fields to a table or come up with another crazy band-aid. It is a snowball.