I once went with a colleague to pick her kids up from nursery. She was a deeply ambitious deputy head, and worked long hours in school - so her kids were there from first light to 6PM every day. She said she liked this nursery as it had longer hours.
I'd rung around a year or two before - including ringing the local council - re. where to get a nursery place for my own son, as I went back to work as a teacher. And coincidentally, I'd asked about this same nursery as it was near my house.
The woman on the phone from the council tipped me off about this one nursery, she said, which they were currently investigating for suspected child abuse. She said she wasn't supposed to tell anyone, as they were 'only' being investigated and nothing had yet come to court... but she couldn't in all conscience say nothing. I promised I'd keep quiet about it. But when colleague was giving me a lift home and picking up her kids on the way - I was horrified to see it was the same nursery the council worker had tipped me off, about.
And the kids were all stood in the window. Just staring out. Desperate for parents to show. I asked colleague if they were always stood in the window (certainly never happened at any nursery my kids went to, before or since). She thought nothing of it. I then told her what the council employee had told me.
Last I heard, ambitious colleague's kids were still there.
My own son is nearly 30 now, so those kids will be grown up as well. But that was one reason I stopped teaching - seeing how ambition is so ugly, it even makes people try not to see the obvious. She was so desperate to appear 'a good worker' and get promotions, she didn't care where her kids were all day.
To me, the sight of those little kids all with their faces pressed up to the window, spoke volumes.
I'd ring SS but don't hold your breath, OP. In my experience, they do nothing and believe whatever they're told.