This is a common question and concern amongst employers.
First of all, what you cannot do is fire an employee for being sick, and obviously you would want to work with the employee to accommodate any serious illness/disability/issue that is effecting their attendance.
With all that being said, you can and should address any attendance issues in your business. If you cannot reliably depend on an employee to be at work and do their work, you cannot run your business. Too often employers are unwilling to address attendance issues because on their own, each absence is reasonable, but collectively, it isn’t.
This may or may not be grounds for progressive discipline, but you are definitely within your rights to say to the employee that their collective absences are an issue, that you feel you cannot rely on them being at work, that there performance is suffering due to the absences, and that you need them to make arrangements so that they can reliably show up to work. I caution you, however, to address this solely on a performance and attendance issue – DO NOT make the discussion about sick time, family priorities, or anything other than performance and attendance.
In addition, try and work with the employee to come up with a plan to correct the issue. Maybe they need to move to a flexible work agreement (if possible), maybe they need to adjust their starting hours, maybe they need a work from home agreement, or maybe they would be better off transitioning to a contract role based on deliverables. There is more than one way to have work done and the traditional model of clock-in and be present for 8.5 hours is no longer a required staple.
I don’t know the ins and outs of your organization, but maybe some flexibility in work arrangements is a better solution than firing, recruiting, hiring, and training.