Well the part of the word poly is derived from polymer. Polyurethane is essentially a plastic coating. I don't see how she would be alergic to it once it's cured. The oil based finish does contain linseed oil though. You may have to start using all water based products.Dont remember what Minwax stain I used last time, oil or water. And I did use a poly coat (dont remember if it was water or oil) on said stain. I havent tried linseed yet.
I just use polycrylic. It's available everywhere. Any water based polyurethane is incompatable with linseed oil. You either need to let the stain dry 3 days to a week before applying the water based polyurethane or use Zinsser Sealcoat shellac as a barrier coat first. In you case that might be advisable anyway.Before I get started on my projects , sounds like Ill go ahead and,
Get a peace of hardwood, a few coats of linseed and a few coats of water based poly?
Any thoughts on steps or Linseed & Poly brands?