so many brands that require buying the extras (special batteries and chargers)...

for just a few dollars more, why not really simplify things and get your ma a simple tough 1xAAA (using regular alkaline or disposable lithium) 300-lumen american-made-&-warrantied 3-level small flashlight that she can always have on her?

Sureifre Titan Plus
http://www.surefire.com/titan-b.html