My workplace doesn’t have a policy either. Because it goes without saying that this is time theft. It’s like suggesting you have to write a policy that says “during working hours you will work”.
I had a direct report do the same, including answering Teams calls while holding a toddler.
I had to face into it in an “informal” call, taking along examples of how they were missing targets/missing meetings etc. which I wrote up afterwards and sent to them.
Incredibly, they initially denied it was an issue. I had to point out that they had been on Teams with their child! Then said it wasn’t their preference to use nursery, that it would have a financial implication (no kidding!!! How did they think the rest of us did it!?!).
Agreed 5 weeks for them to resolve it, missed deadline. Thankfully resigned before the investigation call. (Resigned to take up another full time wfh role).
What I had been doing, which would have assisted in the investigation meeting, was sending contemporaneous notes to our HR partner. So just a note saying “file note. X has not attended today’s meeting with no apologies given”. Or “file note. Client Y advised that during last call with X, their child was present throughout”.
It really helped me to be more factual and not struggle with thoughts of “am I making this into something bigger? Am I over reacting?”