Preface: My grandmother knows little about Home Improvement or Repairing;
please keep answers basic and explain as if she is 10.
My grandmother lives in a new condominium in Canada, built in 2011 that has Popcorn Ceiling or Stucco Ceiling (hereafter SC), that must be repaired because some water leaked from above.
Yesterday, the craftsperson applied some Patching Compound (similar to these pictures in this article) but has not painted, sprayed, sanded anything yet. He said that nothing should smell and that he must return to complete everything his later this week.
Problem: My grandmother can already smell an odor that she finds difficult to describe, but please comment below if you can describe it and I can confirm or supply more details.
Does this odour harm or impinge on health in any degree?