If she has arthritic hands, she might not be able to hold any bins steady, and at her age, the "shakes" are fairly common and a lightweight bin will make that worse.
So a Canon 8x25 IS might be the best solution.
It's a good match for her small entrance pupils, and at $235, it's within her budget even after you add 20% VAT.
The only question is will she be able to hold down the IS button w/out pain?
http://www.bhphotovideo.com/bnh/controller/home?O=&Q=&sku=245431&is=USA&A=details