Do hens have 40 winks in the daytime?

I have two ex-bats that I've had for a year, neither lay eggs anymore.  One of them has been on Metacam anti-inflammatory for 10 days for tumours, and I need to let the vet know how she's doing.  (The vet doesn't think she needs to be put down yet). 

She seems absolutely fine, except a couple of times she had a nap in the daytime.  One time it was the full head under the feathers sleep.   They also appear to like a lie-in, as it's gone 7am now, and the two of them are just considering coming out of the henhouse.

Do hens get lazier as they get older?

That's reassuring, thank you.

Mine likes to groom on top of a dirt and grit filled plant pot and when she's done she sits down, head tucked in and looks like a white frothy souffle!