Virgin Australia have a scheme called 'family pooling' where all the points and status credits (= tier points) go into the head of household's account. I have used this to my advantage when necessary, but I feel bad about this! At least BA's system lets junior BAEC members build up their own avios, tier point and lifetime tier point balance, albeit within a household account, while allowing mileage transfers between family members when needed.

The only thing I would change in BA's arrangements for child members of BAEC would be to either permit children to join without being in a HHA, or permit HHA members to redeem for third parties - the current system seems designed to force parents into a HHA, complete with restriction on who they can redeem points for, if they want their kids to be able to earn miles and TP. I don't know another FFP with this restriction. The only workaround, which may not suit all, is to have one parent in the HHA with the kids and the outer outside!

I sometimes redeem avios for family not resident at my address (sometimes for family with kids of their own), or for business colleagues or friends, so being tied to a HHA would be a disadvantage compared to being a single member of BAEC. BD's household system, without such restriction, and allowing transfer of miles (though not tier miles) from the individual family members' accounts, was much more family-friendly.