Tricky one...

I'm not type 1, so please just take this as incidental info until someone who knows more about this chips in, but sometimes 'not suitable for diabetics' is a disclaimer they put on everything, just in case someone has a mishap: it appears on Scholl insoles, for example. As far as your cystitis sachets go, it could just be that they are full of sucrose. HOWEVER, please check with other users or a doctor in case it really is something else. It might help if you can put up the brand name or components of the sachets.

It's not that a person with diabetes can't use them. It's that they want you to see a doctor before using them to check if you have a full blown bacterial uti that requires treatment with antibiotics. Diabetics are apparently more prone, so should get checked, take a urine sample to the doctors tomorrow so they can check what antibiotics are needed to treat. If she needs something to treat it now I don't think using the sachets will hurt, but it also won't really treat it if it's bacterial and requires antibiotics, it'll just soothe the symptoms and when you stop taking it will flare back up again, which is why they say diabetics should see a doctor first.

@sadsocks

I'm sure you and your daughter know all this, but I'm just tryng to help. See link below on causes and preventing UTIs. I used to suffer a lot!
https://www.nhs.uk/conditions/urinary-tract-infections-utis/

Suz