I wonder if the broth is a different formulation or different factory from yours and has garlic in it?  Or the Hunts Diced Tomatoes - they have several varieties with garlic - maybe your dad grabbed the wrong one and mom didn't notice?  Or the size/factory/ect. they buy is contaminated?

Does she cook it in a cast iron pot that wouldn't get thoroughly washed with soap and water?

All good points.  And my Dad does the grocery shopping for them....has done it for years.  He's 80 now....and who knows....he's a guy.  He would not be aware what foods are around what he buys. 

When DD first started getting "the feeling" she asked if there could be garlic in the soup. 

Yesterday, DD told me if I ever go off on my own for a vacation, she's locking herself in her own room with a mini fridge because DH only gets it when he wants to and I am standing over him and now my Mom is not to be trusted.  Made me feel sad for her.

Oh I would suspect cross contact with something in the kitchen.  It's what makes me uncomfortable with DS eating things made by someone else even when they're using safe ingredients.

Or the contamination could come from the grocery store like sc pointed out. My store puts bags of peanuts in various places (little stands). I make sure to not get veggies from those stands ever and they put bags if peanuts on one side underneath the strawberries. It was a large strawberry display, so I got strawberries on the opposite side. You never know what people touch--or say if they touch a bag if peanuts and pick up a few bundles of asparagus before taking the one they buy.

Is she allergic to something that could have been cut on the cutting board though?  Is the cutting board sealed with walnut oil (if that's one of her allergens), as some people use walnut oil to seal wood products, which I find very odd because it goes rancid, doesn't it?  I digress.  I would ask your Mom to use a new plastic cutting board the next time and see if that makes a difference. 

Or possibly not thoroughly washing the vegetables before using them?  I've had similar reactions to unwashed apples before (not OAS), likely from people touching allergens then touching the apples. 

What about cross-contamination from utensils?  Knives don't typically go in the dishwasher. 

I hope you can find the source.  And glad to hear your DD is okay and things didn't progress.   

So last night was the semi.  Before the girls arrived I gave DD a mug of vegetable soup my Mom made.  My mom uses the exact same things I do.  Right down to the stock.  Veggies are all fresh. 

But DD ate a few scoops and stopped and said something is wrong.  I have a lump in my throat that is super itchy! It's weird when she swallows.  She also says this has happened before with my mom's soup but usually its even milder and she thinks it's in her head.  She says my soup does not do this. 

She dumps the soup and won't take Benedryl because she does not want to be sleepy at the dance.  I tell her I want her to go to the dance but she won't feel better and get to go until she does.  The good news is the girls who have not arrived yet still have 2 hours to dress and hang out so it's not time to leave.

We agree on a half adult dose and she takes it and after a short time feels fine.  No reoccurance.  No additional symptoms, just her throat.  About an hour later she is laughing and eating snacks with the girls, happy, symptom free.  No asthma or bad gut later in the night.

I call my mom to double check ingredients.  College Inn Broth, check.  Hunts diced tomatoes, check.  Carrots, peas, broccoli stems, baby corn, turnips, chick peas, celery, leeks.....all things I cook with.  No spices or herbs, just some salt and pepper.

I checked with DD again about my different soups and things like wild rice that I cook in College Inn broth.  She says no....she is fine when she eats my food.

Could my mom's cutting board be an issue?  She washes it in hot soapy water, it is wood.  Her pot of soup is huge!  I've got many containers of it, now labeled not to feed to DD.  Whatever contaminated the soup would be diluted a lot. 

I don't know what to think.  But I was very nervous last night.

My mom has been cooking for DD since the beginning.  She knows, she is careful, she reads labels.....but.....clearly something was not right.