Spam, I hope your little one is on the mend & that today goes well for you.
If you are to meet HR, please take ‘friend’ in with you to the meeting as support & note taker. Not yr line manager BTW.
It’s good form to have someone with you anyway but also because you have been through so much & the telling of this, because it is relevant to your absence from work, may be upsettling.
A small point, but pertinent - in one of your posts, did you mention that you are not doing your actual job, but PA/admin stuff for your line manager?
This needs addressing. By how much are you not doing what is on your job description - if you are not doing this work, who is or is it just not being done? Is your manager ‘helping’ you by giving you low priority tasks so that your absence has low impact? Give this some thought.
Not delivering to the job description & a series of unplanned absences (whatever the reason) are red performance flags & HR will seek to resolve this situation.
First steps are to establish that you are working on a childcare solution & show this works
Soooo, fantasy time here, if you can employ directly a nanny or nanny share & it has been established that this works well, might it be worth you asking again through this HR review (which will be open for a while) for a change in working pattern, e.g. same or even a few more hours over more but shorter days ( say Tuesday - Thursday). This can be better for the business than someone in for a couple of days a week.
In my experience, people trip up when a colleague has a regular non-work day mid-week, e.g. Tuesday, & this is perceived as an obstacle to getting things done. Whereas a regular Monday &/or Friday non-work day pattern sits better with the flow of work during the week. Is there scope to reconfigure the days you already have so that they fall optimally in the week.