Of course it's her right and her choice.
Pure laziness on her part. Otherwise she'd have to buy flushable antibac wipes, and the such. Then of.course.after everyone has.left, then clean out the toilet, and sensibly through away the toilet roll.
Of course it's your right and choice to not go.
My fiancee who has been shielding and has a very slight bladder issue (post menopause)! She said she wouldn't go to town knowing there were no toilets (post July 4th and almost all opening up). I contacted one place to find if the disabled toilets with RADAR KEY, would be available ... Yes. So then she felt able to.go.to.town.
We both carry a antibac gel (mine is hung.on my rollator) and we both have antibac wipes (lol pocket ones).
I think if you know people haven't been in contact with covid, there shouldn't be a reason to worry.
Of course you have fucking twats like in Burnham on sea recently who while waiting for his test result went to the pub. Risked the lives of 70 people, and their family's n friends. The pub had to shut again and have a second deep clean.
Becareful out there, be safe, and.practise good hand hygiene.