napping vs off her guard

napping and off her guard both are adjectives.

Word	Noun	Adjective	Verb	Adverb
napping	No	Yes	No	No
off her guard	No	Yes	No	No

As adjectives, napping and off her guard are synonyms defined as:

Other synonyms of napping include off-guard, off guard, off his guard, off one's guard, off your guard.

napping (adjective)	off her guard (adjective)
not prepared or vigilant	not prepared or vigilant