Isolation days question

[wizbit93]

Hi. Can anyone help with this one please?
DD (group A for these purposes!) was sent home Monday morning as a close contact of someone who has tested positive. Although not confirmed, we were told the contact was in PE on Friday. She hasn't been told who it is. She was told to isolate up to and inc Tuesday 22nd. Fine.
Fast forward 24hrs and the rest of the year group (group B) have been sent home (on Tuesday) due to a further two cases. The whole year have now been told to isolate up to and inc Thursday 24th, and to get a PCR on day 5. I have booked it for today as I am classing Friday as the contact.
Is this right? Surely Group A should be let out sooner? Or is it because they spent 2hrs at school on the Monday and could have been in contact with the two new cases?
Thank you

Could be a different case than your DD. Unfortunately as you don’t know who the person who tested positive is, you cannot work out your own isolation dates, so you have to go on what the school has said. You may get a call from test and trace, who will confirm the isolation dates.

Thanks, that's basically what the school said.