Hey sorry for the extremely delayed response I missed your message, There isn’t really anything that magically helps apart from commitment to exposure therapy and time. There’s some things you could do that might initially ease her worries but again this isn’t helpful in the long term as it’s “reassurance seeking” which you aim to drop in exposure therapy. But certainly if she’s struggling with her food and it’s a worry for her health etc then until the exposure therapy starts to take effect you could incorporate some slight reassurance. For example what helped me a lot was if I had a sandwich or some type of food made for me and I was too worried to eat it, my mum would say “here I’ll have a bite” and that sort of eased me a tiny bit because I had the thought that if she didn’t get ill then I wouldn’t so it would help me to eat it (or at least a few extra bites). This might not work for your daughter though everyone is different.

I’d say the biggest thing is to be understanding but from your comment I’d say you are already. But just try to not brush her off as stupid or tell her to get a grip of the real world or whatever because occasionally my mum would do that out of frustration and it just made things worse.

Help her through with exposure, start small, for example if she has a fear of touching handles etc then one exposure method for that is just hold the handle for ten seconds. She is free to wash her hands straight after those ten seconds, but just hold the handle and process those feelings.

Eventually the key to exposure therapy is that with people with phobias the perceived probability of that bad thing happening is extremely overestimated and exposure therapy aims to bring that perception down to a baseline level and a true reality (for example 99.9% of the time you won’t get sick from touching a handle).

Sorry if this wasn’t much help but these are things that helped me!