After a couple of weeks of this happening I factory defaulted the fone and left it a week and it seemed to have fixed it. I restored the backup, upgraded the default apps and put back Swiftkey, Whatap and Air NZ Mpass the three apps she mostly uses and left the rest as she also has a tablet. It seemed OK for a further couple of weeks but it's started happening again.
I've told her next time it happens take it back to the local Telecom store and show them as no one will believe it if you take it back working again.
No doubt it will be sent away with some reason like "water damage " or the like being the answer from Telelogistics because it's out of warranty at which time she will have a go at the CGA.
Anyone seen this before and if so any ideas ??
If we weren't treated like a tech 3rd world here and didn't have to jump thru so many hoops I would buy a Nexus 4 and give her my old SGS2