Agave syrup — Food safety facts
Feed with care · Cats · full breakdown on the linked food page
Fructose-heavy syrup. Treat it exactly like sugar.
The full verdict, portion guidance and serving notes are collected on the Agave syrup food facts page.
Short answer
It's not an emergency, but it's not good for her. Agave syrup is pure sugar, which can cause an upset stomach or a temporary sugar spike. Just watch your cat for vomiting, diarrhea, or unusual lethargy over the next day. If she shows any of those signs, a call to your regular vet is a good idea.