Thing 1 has just done two lateral flow tests and had two positive results (she is also clearly unwell). Does she have to get a PCR test (ie leave the house, poorly, come into contact with others, etc) or is she ok just to isolate? Sorry for being so dim.
Don't know the legal answer but, in my opinion, I would self isolate for ten days and not bother with pcr. Here in Portugal they are much stricter with isolating and all close contacts must isolate as well. Schools are using masks indoors.