If you go by her IG she came back the 20th September so her quarantine should have started on the 21st and ended on Monday 5th October. She was out the friday, travelled to London on the Saturday and out in London on the Sunday.
Petty or not she broke her quarantine and in essence the law and should be held accountable for that much like a murderer would be held accountable for murdering someone. The law is the law.
If you look at Anastasia Kingsnorths thread she broke the law too and has been held accountable on there. It’s not petty, if us mere mortals should be expected to abide by all rule, guidelines and laws then so should ‘baddie maddie’. It’s not difficult.