Sibling query

[Bezzyk7]

My son had a sore throat and tummy ache since last Wednesday which developed into a cough when he woke Friday. He had a temperature as the day wore on that lasted 24hours. Got him tested and just had the negative result.
My daughter is now showing the same symptoms, she's had a sore throat for a couple of days, starting to cough today and feeling warm....now my question, if she develops a temperature do I need to get her tested even though its the same cold as her brother?

I would just becaise it could be she picked up covid at school and although it maybe more likely to be same bug as brother it could be a different one.
My daughter had flu in jan but son didnt. Son had chicken pox but not daughter last yr