Households
A household groups the people who live or are cared for together. Somebody can be in more than one at once — that is what shared custody looks like — and a membership is ended rather than deleted, so the record of where someone was still answers.
Roles
A role is standing permission. You can only hand out roles you hold yourself, and a revoked role is kept as a record of what was once allowed.
Temporary access
Access you have passed on to somebody else, and access somebody has passed on to you. It always has an end date — access with no end is a role, not a favour — and it can be shortened at any time, but never extended: longer access is granted again, by a person.
Guardianship
Who is recorded as responsible for whom. Nothing here was guessed from older data: every entry was added by a person, on a date, with somebody accountable for it.
What people can do
Pick somebody to see exactly what they may do in this family right now — and, where they may not, the reason.