PLEASE help. 7 wk old chick twisting and stretching neck

[lilyegg]

My seven week old salmon Faverolle mix is acting lethargic, is stretching her neck and twisting it in circular motions, has a little croak/deep sounding noise after peeping. Worried she might have Marek's. no balance problems but her wings are lowered a little. She was ordered from MPC as a Faverolle but BYC members told me she was an obvious mix of a Faverolle and an unknown breed from the hatchery so I wasn't so concerned about her stance or wings being a little droopy because I didn't know what her other parent with the unknown breed was/how they were built and carried themselves (has had droopy wings for a week or so now) but the neck movements are new and scaring me. Please help!!! She's eating and walking and drinking normally.

 

[lilyegg]

She also isn't opening her mouth or wheezing when she breeathes

 

[lilyegg]

She hasn't done the head twisting thing this morning and after work I will check on her again but still worried about Marek's, a respiratory problem, or gape worm. She's not gasping or opening her mouth like she's yawning but she was moving and stretching her neck out quite a lot and moving her neck in a weird way.