You say she smells musty, do you mean the smell of mildew or mold?
We have a client who comes in our office and smells like mildew. She is well to do, very clean in appearance and dresses nicely. I finally discovered that she lives in a 100 year old Victorian home in a nice part of town, which made think, her old home probably has some moisture problems and, as a result, her clothes absorb the mildew smell in her home. She is obviously unaware of her odor (like smokers who can't smell smoke) and so this poor woman runs around smelly.
Now if her husband does not smell, well, maybe he keeps his clothes in a different closet.
Just a thought.
Another consideration would be any medications she takes. Certain drugs can change body odor.
Good luck on how you decide to handle this.
LM