sorry I can't help with the first Q
re your nan - It really depends how long she's felt like that & whether she has other symptoms but I live in Derbyshire & we have a 'flu' type bug going round that makes all your insides hurt as you you describe. Makes you feel awful & seems to affect everything from your tummy to your bladder to a period type pain.
Tell her to take paracetamol & drink plenty of fluids but if she's not any better by Thurs maybe she should see a GP/nurse before the xmas break.