So 20-30 yds is close enough?
If she was at her home then the cat was on her property. Its not her job to police other peoples pets.
LOL, look at that brush, do you really think she was up to 30 yards away, and yes, you should be able to tell if the cat is a well kept pet, or a feral cat, especially when identifying your target of a neighborhood cat, before you kill it.
This is one of those examples of the pet already having been killed, so the mistake is obvious, the shooter didn’t know what she was shooting, or she did.