Hen breaths heavy when she sits down

[cmclean]

I have no vet who treats chickens so I am hoping someone here can offer advice. My 2 year old Buff Orpington hen has been breathing like she is in distress. She does it when she sits down to rest. She opens her beak wide with each breath she takes in. This is a very exaggerated motion, with her tail and body moving up and down. I don't see anything like it when she is up and walking around. Anyone have an idea what might be going on? Cause for concern?
Thanks for any help or advice.

 

[casportpony]

Get some gloves, KY Jelly and gently check her for a stuck egg.

 

[cmclean]

How far do I probe?

 

[casportpony]

Couple of inches, but do it gently.