My mother, now a widow, has Priv Travel as my dad used to work for British Rail before he retired. I think she gets about 18 free days travel a year.
What is the situation regarding upgrading to 1st Class.
For example if she was travelling on a Saturday with EMT from Nottingham to St Pancras would she be able just pay the £8 upgrade and be able to travel in 1st Class?
It's just that 1st Class AP tickets are so reasonable on Saturdays that I always travel 1st Class but whenever I am travelling with my mother i always book standard class so that we can travel together. I am sure that she would be very happy to just pay the upgrade.
Right, unless your mother has free 1st class travel then she is not entitled to upgrade to the first class privilege fare.
For example, if your mum dated a box and travelled in 1st class from Nottingham-St Pancras, she would be excessed the difference between the privelege standard class fare and the full public first class fare:
£98.00 First Open Single (undiscounted)
£16.50 Standard Open Single (PRIV rate)
The charge your mother would have to pay is £81.50 to use first class.
HOWEVER:
Some Train Operating Companies have a product called 'weekend first' which allows anyone* to upgrade to 1st class by buying the supplement.
In this case, (East Midlands Trains), your mother would have to date a box, or purchase a standard class priv rate ticket, find a seat in first class and pay the £8 Weekend First supplement. For a return it would obviously come to £16. The answer is that nothing prevents holders of rail staff travel facilities from taking advantage of the Weekend First product.
This is valid Saturday and Sundays only.
The cost of weekend first varies by train operator and not all train companies offer this product.
*with the exception of some 'Advance' ticket types, these are not available with PRIV discount anyway so are irrelevant to your query.