I was hoping someone could advise me on what you can do in this situation if the employee is employed for a company in republic of Ireland.

I have a manager who is 2 and half months into their probation period.  Serious concerns were raised that what she said she could do at interview were not being put into practice in the workplace which is a problem as these concerns are around the backbone of the job she has in the company.  So we scheduled a formal probation meeting, detailed the concerns, gave the right to be accompanied and advised that depending on the content of the meeting, then one possibility was that we could terminate the employment.  On the morning of the scheduled meeting they emailed me to sat that they had decided not to engage in the process as doesn't agree with what was said or that we were calling a formal meeting to discuss.  I reached out and encourages her to reconsider and explained that it was important that she was able to present her case and put it off for 2 days to give her a chance to reconsider attending and also gave her the option of submitting a response to the concerns in writing if she wasn't willing to attend in person. I made her aware that the rescheduled meeting would go ahead even if she didn't engage or put in a written submission.  today she has rang in and said that her Dr has given a sick line for 2 weeks.  Can we still go ahead with the meeting we scheduled even though they are off sick or does anyone have any other advice they can give me?