There is not such a thing as "family catchup."

HSA accounts are individually owned.

The people are entitled to contribute by being covered by a HDHP.

There is a provision that a person who reaches the catch up age (55) then they can add an additional $1,000 to their own HSA account.

The contribution to the HSA account is limited by the plan they are enrolled in.

The other parties in that plan also can put in an additional $1,000 into their own HSA accounts when they reach 55.

So, a spouse might put only that additional $1,000 in their own account at 55, assuming the main covered employee with a family plan through work might put the entire family amount in their own HSA account + their own $1,000 catch up amount when they reach 55.