I've only read OP's posts so sorry if I'm repeating.
At the moment, YABU. We are still in unprecedented times. I'm a single parent, with 3 children & a high-pressure job. To deliver my work commitments, I work early & late, and weekends, to an extent I didn't pre-pandemic. That then takes account of the time I need to deal with kids, bring / collect from school etc.
However, this doesn't mean that you should support a drop in productivity.
If this is an issue, start dealing with it, case-by-case.
On the team I manage, productivity has not dropped, and has increased in many ways. There are some who are not working to the level expected - but they are staff who weren't doing so when we were in the office.
My rule of thumb, and as supported by senior management, is that we focus on the output rather than input (within reason!)
That's served me well and avoided resentment from staff, if we went down the instructive route that you are planning.
In my own case, I'm working very productively, and while it's sometimes really tiring for me, I'm so grateful I can do my work effectively & also provide for my kids. Believe me, my organisation greatly reap the benefits from my gratitude!
I note you mention client interactions which need to be free from interruptions. I get this. Most workplaces have some issues like this, including mine. There's absolutely no problem with making this clear. In my case, I do get some help externally when I have these situations. Most professionals will do likewise - might be childcare, might be their spouse, might be hep from their parent.
It's no business of yours what arrangement they make, as long as they operate professionally. If they are not doing so, individually, have a discussion with them, but focus on their work outputs, not whether they have childcare or not.
In my experience, any blanket statements will really put people's backs up, including those who have given over & above.