Day 0 Mum gets it
Day 3 Dad gets it
Day 3 DD1 gets it
Day 10 Mum free to leave house
Day 13 Dad free to leave the house
Day 13 DD1 free to leave the house
Day 17 DD2 free to leave the house
Day 20 DD2 gets it
DD2 has to isolate for 10 days (or until better).
Do the rest of the family have to isolate?
I'd say no, but Test and Trace say yes.
Cases all symptomatic and confirmed with positive test. Girls are older teenagers.