As Nick said, Steel's and Edinburgh Coop are the Specialized dealers in Newcastle. There's also Evans down at the Metro Centre. My personal preference would be Edinburgh Bicycle, although service and "knowledge" will depend on which member of staff you get (in either shop).
To be honest, I think that it's often better for noobs, who don't know anything about the glaring, let alone subtle differences, to just find bikes that they like in their price range and take them outside for a spin. If they have any specific questions after trying a bike – in regards to fit/set-up, for example – then they can discuss it with somebody. As long as they make it clear what they want to use the bike for, they shouldn't be sold an unsuitable bike; and trying out all options means that they'll get the bike that suits them the most without having to try and translate all the babble and sales pitch. I've overheard, and been told personally, some absolute nonsense in every bike shop I've ever been in – so sometimes I think that "ask no questions, hear no lies" is sometimes the best approach.
If it would be of any help to you both, I could ask my partner if she'd be willing to go in with her. She's an experienced rider, both MTB and town/road, and has a pretty good sense of bike fit. My email is in my profile if you'd like to get in touch.