It's taken the joy out of a lot of things she enjoys, especially cooking. She's seen a few ENT doctors and they all claim it's not coming back without any clear solutions.
One usually recommend four oils (of high quality preferebly): one citrus, one mint/eucalyptus, one spicy (e.g. cinnamon) and one flowery (lavendel did wonders for me, then geranium) to start out with. Smell each oil for 20 seconds every morning and evening, while thinking of/imagening the thing you're smelling. Since it's a neurological issue, the last thing supposedly helps. It usually took me 2-3 weeks from starting training until noticing any (very minor) effect at all, and much longer to regain a lot of it.
Sorry if she's already tried, hopefully it's useful for others. It can take a long time for the training to work.
Internet says it was Ben.
Ozempic and similar medications have an even more subtle effect. Food is still just as enjoyable but the attraction to that enjoyment is gone.