My sister (S) has worked as a receptionist in a health centre for the last 14 months. She works part time mainly evenings and weekends. 
Approximately 5 weeks ago (mid June) her line manager took her to one side and commented that there had been hours on her May timesheet which she had not worked and this could be classed as fraudulent. S was obviously concerned about this as she didn’t believe she had made any incorrect entries. She asked to see the timesheet but the line manager never produced it.
A week or so later she saw the General Manager and asked her about the timesheet. The GM said she would find it. She returned later in the day and they had a chat. 
It was one entry, the last shift she had worked in May, when she arrived at work there was a note reminding her to complete her timesheet for the month as they would be sent to payroll on the 1st she brought hers up to date, including that shift. Unfortunately for her, and unbeknown to her at the time, she was taken ill during the shift and sent home by the GP that was on duty. The GM agreed that this was a mistake and not a fraudulent activity. S was relieved and stopped worrying about it.
On Monday of this week, so 4 weeks later, she received a call from HR asking her to attend an investigatory meeting on Wednesday relating to the timesheet. A letter was going to confirm this but has not been received.
I advised her to call the GM and clarify their discussion of 4 weeks ago. GM said she knew nothing about the hearing and said she would accompany S to it.
S arrived for the hearing. GM was not available. The hearing was led by HR and the site union rep, who S did not know as she works Mon-Fri 9am-5pm, was also present. The letter which never arrived was presented at the start of the meeting and was addressed from the GM, who had said she knew nothing of the hearing.
The meeting was concluded and S was notified that a letter would be sent to her confirming the outcome.
The GM has now phoned S this morning (Thursday) and told her she is suspended on full time to allow further investigations to take place.
This suggests to me that they are looking for a gross misconduct dismissal.
It seems very harsh to me for one entry on one timesheet – or maybe I am too close to it and not seeing the wood for the trees.
What also concerns me is how long it has taken them to get round to this.
Does anyone have any advice that I could pass on?

Thank you