To think she doesn't *really* have coeliac disease?

I've definitely known of people with CD who still eat the odd bit of toast or whatever. They might be able to do that and just deal with low level gastric symptoms it causes - like a runny poo, feeling sick etc. However CD is not just an allergy or intolerance - it's an autoimmune disease. So if she's a true coeliac, she'll continue damaging her small intestine for as long as she continues eating any gluten. This can have longer term consequences for her health than a bit of acute diarrhoea. The persistent damage to small bowel can increase risk of cancer.

I was diagnosed with CD in 2008 and have been GF since then. All these years of being GF mean that now if I'm accidentally exposed to gluten, I have a much more severe reaction than when I gave it up (violent vomiting within 2 hours of consumption followed by diarrhoea - both lasting around 6 hours).

So I guess it's possible she's a coeliac and eating gluten but ultimately if that's the case, it's her own health that will suffer if she keeps doing that.

Coeliac isn’t an allergy. Some people knowingly decide a small amount of gluten is worth the consequences but for most people with the disease, once you cut out gluten altogether it’s horrendous to have even a small amount in your diet.

She may have a gluten intolerance - but that's not coeliac disease.

Coeliac disease is an autoimmune condition, and a speck of gluten on a worksurface / a knife previously used to cut ordinary bread, would literally poison her. She'd be very ill for days.

Has she had it diagnosed through a biopsy? If not, she's bullshitting.

YANBU. I have coeliac disease and accidentally ate a gluten containing item this morning - I was violently sick several times and then had to sleep it off for a few hours. Will be a couple of days before I feel completely 100% again.

Lots of people are intolerant of gluten without actually having Coeliac disease. They might "just" get cramps or pain or diarrhoea if they eat gluten and some might decide that these symptoms are worth it for a treat.
Actual coeliac disease causes damage to the gut lining not just the runs.

It's possible to have gluten intolerance which means gluten makes you uncomfortable and a bit ill, but you can handle it.

Coeliac disease means that you can't process gluten at all , the gut wall is physically different in people with the disease. Someone with Coeliac disease would be horribly ill, possibly for days, if they eat a gluten biscuit or bread by mistake.

For example, even fish being tossed in normal flour before being fried would make them ill

YANBU. She doesn’t have CD. At most she may have a sensitivity to gluten.

She sounds batshit. Can you leave all the hosting and shopping to DP when she visits?

No, I don't think you can be mildly coeliac so if your post is the truth then she's lying, or she gets very ill after seeing you!

What did she say when you wouldn't apologise or give her your personal to do list?

What does she say when you point out the biscuit is not GF?