Need to look on a real computer -- but one rule of thumb is can you count six or more ribs over the heart on radiograph. On that basis I'd say there's a possibility of slight enlargement that may benefit from a trial of benazepril based on clinical sign.
This is on my phone, though! Will take a better look at it later.
VERY VERY VERY WISE of you and your vet to leave her incisors alone if they are not causing her any problems.