Chicken foaming of the mouth

[BigBirdy]

I have a year old chicken that just started foaming at the mouth also. What do I do? I have 4 others that are all just fine. They roam my back yard with my ducks and are put up in their coop at night. She was on my back porch when she started. I have tried to massage her neck and given her clean water. She is not making any rattley noise or anything like that. My kids saw her spit up some grass but she is still foaming a little. If she is not getting enough grit, can I give her some now and it help her?

Mines foams from her mouth too, but I think she gets enough grit because she's free roaming.