Chew Chew Train
The girls do love their bones.
They often lie near each other as they gnaw away. Sometimes butt to butt. This particular evening, they formed a single file. A chew chew train (groan).
In the second photo, I caught Meadow with an odd expression. It appears as though she's curling her lip, but she's not. She was catching her breath and getting ready to lick her muzzle.
After they've removed the marrow, they'll switch bones. Just in case the other one missed something.
I've often watched Maia slowly and carefully approach Meadow, who keeps her bone between her paws. Once Maia realizes Meadow isn't guarding or feeling possessive (no curled lip, for example), she will take her bone, snatching it right from under her chin. If I'm watching, I praise Meadow lavishly for allowing this bit of big sister dominance.
I always hold my breath when this happens. But Maia reads Meadow well, better than I ever could. And Meadow, I'm sure, realizes she can have Maia's bone. Maia doesn't hoard. They've worked it out, learned to share in their own way. Most people could learn from them.