An employer cannot just use 'seniority' as a criterion for redundancy - many other factors in a selection matrix must be used to ensure fairness.
If this is the case, then the situation potentially is 'unfair dismissal' (Based on English law).
Also, many employers try to manipulate or 'tailor to fit' their selection process to ensure certain staff are retained.
Check your home insurance policy to see if it includes legal assistance. If so, it will almost certainly include employment disputes. Redundancies are a potential minefield but ultimately, have to be implemented correctly.
BTW, unless certain discriminations have occurred, generally, one has to be employed for 1 year to claim unfair dismissal.
Talk to an employment solicitor and get out her contract to see if they have any obligation to keep her rating current for any period after redundancy.
If lieu of notice is given - say 3 months, then all of the redundant persons terms and conditions are still in place for that period even after they have left the company. For example, company cars can still be retained for the duration of the notice period.
passy