Adjective for the unfortunate side of having a "good sense of smell"

I think that a comparison or simile would serve you better here than an adjective:

Her sense of smell is as keen as a great white shark's.

for example, or

She has a nose like a bloodhound's.

although the latter may cause people who've never seen your mother to imagine her with a long snout, droopy ears, and doleful eyes.

My wife's sense of smell far surpasses that of anyone else in our family, and when she makes a pronouncement based on her olfactory acuteness, we simply say, "The nose knows."

There are two adjectives that indicate a good sense of smell but not very useful for an everyday speech:

sharp-nosed

having a keen or sensitive sense of smell.

^{http://dictionary.reference.com/browse/sharp-nosed}

Sharp-nosed is not common in this sense and it is usually used to mean a thin, pointed nose.

osmatic

Having or characterized by a well-developed sense of smell.

^{http://www.thefreedictionary.com/osmatic}

And osmatic is usually used in medicine and biology. [Another related term is hyperosmia (hyperosmic as an adjective) which is an increased olfactory acuity (heightened sense of smell), usually caused by a lower threshold for odor - Wikipedia]

In the end, your best bet might be not using a single word but saying "having a good sense of smell" or "having a strong sense of smell". Or maybe a simile like "having the nose of a hound".