www.independent.co.uk/news/uk/politics/sajid-javid-dominic-cummings-fires-special-adviser-johnson-brexit-sonia-khan-a9085056.html
I am a line manager and mere mortals like us have to handle a dismissal in an appropriate way:
Invite the individual to a meeting in line with company policy;
Let them know beforehand that dismissal is a possible outcome (though never a foregone conclusion);
Allow them a companion to the meeting;
Let the individual have his/her say and consider this before reaching decision;
If we dismiss, explain the grounds for the dismissal (conduct, capability or whatever);
Allow them the right to appeal the dismissal.
It looks as though none of this was done here; apparently the Government is arrogant and high handed enough to think the law and good practice don't apply to them only the rest of us.
If she has more than 2 years service she has a lot of rights, and may choose to take this to an employment tribunal; in which case she will probably win. And guess whose money will have to be used to compensate her?