possessives - “in you_ and your family’s best interests”

I’ve seen this picture of a leaflet being tweeted today. It’s supposedly issued by the UK government and distributed widely:

Am I overlooking something or does it really contain the grammar error discussed in "You and your" vs. "Your and your"?

I could see the possessive ’s applying to the whole phrase

it is in (you and your family)’s best interests,

because the plural interests wouldn’t properly match singular your, i.e. it’s a short form of either of

• it is in your best interest and in your family’s best interest


• it is in your best interest and in your family’s best interests

instead of

• it is in your best interests and in your family’s best interests