Child has to self isolate

[KungFuPandaWorksOut20]

I've googled and genuinely can't find a straight answer at all, was hoping for some clarity or where I can find an answer.

Child's class has too self isolate due to a confirmed case. Notified child's dad and neither of us know if she is allowed to go his for half of the holidays as planned.

Can the child go or is that a big no no?

My DC have both been to their father’s during isolation. Youngest DS has just had to start isolating for the 2nd time consecutively, so wouldn’t have seen his dad For a month if we didn’t stick to join custody arrangements. Equally, it could have easily been me who didn’t get to see him for a month. That’s absolutely not happening. Don’t care if it’s against the rules or not, my children have had enough loss and disruption to their lives this past year.