Don't be too pissed with her mate as I reckon most of us would have done the same in her situation, with it being her Dads funeral it would be neigh impossible not to interact with other family members.50/50 my wife has it after attending her estranged dad's funeral a couple of weeks ago.
Told her if she has to go, just attend outside the church and leave after everyone saw she was there.
She disappeared for 3 hours. She eventually told me she was in contact with family to some degree and one that was around her dad when he passed.
Her symptoms [cough, phlegm, fever] started in earnest yesterday and an A&E crew came to check on her cos of her heart. She's on really strong abx to, hopefully, make sure she doesn't get worse.
I'm mightily pissed with her for ignoring my advice.
I was at my brother in laws funeral a day before the lockdown and have every intention to do what you suggested to your wife but as soon as I arrived people were walking over and greeting me like most folk do, you would need a heart of stone to ignore them in such a situaltion.
I wish her all the best mate and hope everything turns out fine.