Most of the good stuff about how such meetings should occur is here.
http://www.direct.gov.uk/en/Employment/Employe es/ResolvingWorkplaceDisputes/DG_10028114
Some of this is statutory, some is just good practice, and will be part of the ACAS Code of Practice.
Everyone should have the right of appeal and there is some material on it here.
http://www.direct.gov.uk/en/Employment/Employe es/ResolvingWorkplaceDisputes/DG_10028115
Even if the dismissal was for gross misconduct (was it?) the process followed should have been the same. However unless your friend has a minimum of 12 months continuous service there may be nothing she can do about it - because she cannot take a case to an Employment Tribunal without such a length of service. Unless the dismissal was because of pregnency, attempted use of a statutory employment right, or membership of a TU, in which case the min. 12 months service does not apply.
Some (less scrupulous) employers don't follow the good practice guidelines because they know there's nothing the employee can do about it in the above situation.