Thanks so much for all your advice. It's actually very difficult to get bikes here because of customs restrictions, it takes ages! The Specialized shop we usually deal with still have not got the 2014 bikes that were supposed to arrive last November, then January, then February....to order specially will take a long long time and cost more...

Anyway we went back yesterday, spent more time there and I think after all the 50 frame will be fine. We were able to move the seat back more than we initially though, and the reach is not too much even with the 120 stem. As it's a 2012 it will cost us quite a bit less (under 3k) which is advantage too. Actually its very lucky they are willing to sell just the frame as this is a complete bike really and it's very hard here just to get a frame........shame it looks so nice with all the matching components but we can't afford the whole thing!

By the way her crank size is 170, I think this is correct for her.

Anyway, once again many thanks - we should be getting the bike next week.....