Should I be worried about this black mark on my hens face?

[jen61871]

If I was told her true age this hen is around 2 yrs old. Since the summer she has been acting old and fragile. She spends most of her time in the coop resting, she has a hard time walking (as if she's aged), she no longer lays.
I finally moved her to her own coop ans run and no longer let her out to free range because I am sure my young and quite healthy roosters would have killed her.
She DOES have a good appetite and drinks fine. Her stool is on the looser side and greenish.
Now my question is this black spot on her face. Is this anything??

 

[Eggcessive]

The black spot may be from a peck or injury that has bled. She looks like a buff orpington, but has some odd features, such as an odd parrot beak and seems to be rumpless.