So the 4 month old is content on the mat for an hour?
That's a great schedule. I have a LOT of work to do to get to that point, lol.
They're both as sweet as can be, with great temperaments and very minimal fussing. They also really enjoy lying on a blanket and looking at one another...but they're generally not awake at the same time.
I'll try waking the sleeping one up in the AM and putting them down together, and see if that helps.