We've had this plant since 2010 at least, and it's never flowered. I didn't even know they could flower
Here's a photo of the big one. The part not directly facing the window is looking a little anemic. Maybe I should rotate it every few days?
I now think it is probably Sedum album 'Athoum' and that the container had been mis-labeled at the garden center. I can't find any irish moss anywhere that looks like this.