She gets very scared cat. 10 years ago we tried to introduce a kitten, as a playmate for her, and she went into hiding for 3 days. After we gave the kitten back she went back to her normal self, that's how we know she'd freak out about something unexpected.
Thank you all for your inputs...
Our cat is going on 22 years and she has just started wobbling.
My husband rescued her and she's never been to vet since the age of 2 and we know that she'd freak out if we took her to one now.
We suspect that she was the runt of the litter.