This link will tell her how much redundancy pay (Which is paid without deduction of Tax and National Insurance) she would be entitled to receive following compulsory redundancy -
http://www.berr.gov.uk/employment/emplo ... 33157.html
In addition she should be entitled to claim Statutory Notice Pay which is the equivalent of 1 weeks pay for every complete year of service, upto a maximum of 12 weeks. This is subject to deduction of Tax and National Insurance, the equivalent of any benefits that could have been claimed and any wages earned from a new employer, if new employment had been found during the statutory notice period. The idea being that on receipt of that Notice Pay, you are no better off if you had found new employment but equally you would be no worse off if you didn't.
She will be able to claim wages that are due for this month and any unpaid holiday entitlement that is unpaid. This will be also besubject to deduction of Tax and National Insurance.
All the payments are however subject to a maximum limit of £330 per week or £1430 per calendar month. If you earn less than or upto that limit you will not be affected. If you earn over that amount, you will be paid up to that amount and the balance will rank as a claim in the Insolvency.
The process of making claims through Redundancy Payments Office is much faster than it was and they currently aim to process 78% of the redundancy payments claims within 3 weeks and 92% within 6 weeks.
The most important thing to do though is sign on straight away.
Tell it like it is.