Welcome to BYC.
Ruby probably inhaled a feed granule while eating and it got lodged in her nostril, then hardened. You can try removing it yourself or wait to go to the vet.
If you decide to remove it yourself, smell her nostril first, close up. If you smell a foul odor, dont mess with it, just take her to the vet. Also, look inside her mouth for any lesions.
If there isnt a foul odor nor lesions in her mouth, wrap her snuggly in a towel including her legs/feet, with her head sticking out the front of the towel. Then lay her on her side, use an old rag soaked in warm water and apply it to her nostril to soften up the debris.
Then use a toothpick to gently loosen and pick out the debris as best as you can, tweezers may be needed also. You can use an eyedropper containing warm water to further loosen and soften up the debris. Then use a Q-tip to further clean it out.
The nostril will be enlarged after reaming it out, but it will be clear of debris. It will take time for the nostril to shrink back to normal.
