If you’re in level 0-3 then other friends or family can still look after your children, in line with the restrictions on numbers. This means that for levels 1-3 the caregiver can only look after children from one other household. So, for example, a nanny-share wouldn’t be permitted, as that would involve children from 2 households and a nanny from a third household. If a grandparent normally looks after cousins, then in levels 1-3, they would only be able to look after one set of grandchildren at a time.
At level 4, you can only ask friends and family to look after your children in their homes if you are an essential worker. If you are an essential worker and your child has as disability that makes moving households difficult, the adult looking after your child can come into your home, rather than the child going to their home. Our page on childcare explains more.