Thanks everyone, plenty of options to consider. A phone won't be one of them though. The sight of one would trigger immediate & illogical technophobia and a total unwillingness to consider using it. Or, better put, she would say she would use it to us just to keep us quiet, then immediately put it away somewhere to gather dust like the other 'simple' phones we've given her before once we'd left. Of course, there's no guarantee she'd use a pendant/fob, but we have to try something after her recent falls.