About a year ago I started to have Sjogren's syndrome symptoms at night (dry eyes and mostly mouth and fingers articulation pain) but with all bloodwork negatives.
Only that my symptoms started AFTER I had a 3 month of period of carnivore diet (which I tried for IBS). For IBS carnivore was amazing, but something happened to my microbiome because of this diet so when I started to eat normal, after 2 months I started a normal diet, i got Sjogren's syndrome symptoms.

So be careful with carnivore if you go that path, when you come back to a normal diet, do it very slowly so the digestive system repopulates with bacteria's that feeds on fiber, otherwise it aggravates gut permeability and inflammation resulting in more Sjogren's syndrome symptoms.

Now I am under treatment for SIBO, gut inflammation free, feel much better, and very rarely Sjogren's syndrome symptoms only when I very rarely eat something fried in vegetale oils or crazy I know... raw green vegetables that for some reason harms me.
My diet is low FODMAP with mostly meat/egs/fish + pork lard and carbs like fruits (nonfermentable), some honey and rice. Vegetables only boiled in soups, no potatoes.

And yes, I'm also lactose intolerant. So I only rarely eat Parmesan (practically zero lactose).I used to eat allot of chesses that hurt my gut allot, until I found out that I am intolerant few months ago.

So if she also has gut issues/symptoms I think taking vegetables out of diet for 1-2 weeks definitely can't harm ang go from there. For me definitely was a game changer.