[markers]

Has she been doing essential oil training? As far as I know it's the only scientifically validated method and it did a lot for me (although at soon 2 years my taste/smell is not fully recovered). I know it worked as I only regained the smells from the oils initially. Flowery oils were specifically good, as they likely contain thousands of different compounds that you find in many other smells.

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.