tail down, no eggs since friday

[melloladies]

I have a 13 month old EE hen that I got about a week and a half ago. She laid 5 eggs out of 7 days, then starting Monday, I noticed her tail was drooping and she doesn't seem very peppy. I also haven't seen her eat at all today. She hasn't laid at all since friday... what should I be on the lookout for?
I'm totally new at this, so I've never "checked a chicken's vent" or checked for mites or anything. She had just come of a worming treatment the day I got her (Ivermectin??? Did I get that right??) I'm just not even sure if I should be worried or not, but of course, I'm freaking out!!!
darn chickens get under your skin so quick! I love her!!!

This is a re-post. I had it in another section of the forum. Hoping to get some answers by posting here instead. Thanks in advance!

 

[RM44]

Do you know how to check for sour crop? I've been through it twice, and both times the first thing I noticed was the chicken acting strange (not hanging out with the rest of the flock), not eating, and looking droopy.

 

[melloladies]

is sour crop the soft and squashy one? I gave her a hb egg and some yogurt when I got home about an hour ago and let all the girls out in the yard. She seems to have perked up. Gobbled up her treat, that's for sure! She is a new girl, so is it possible the stress of moving just hit her a bit late, and that's why she isn't laying?? As soon as I let her out, she was jumping up on things and exploring... I think she's used to more free range time than I normally give my girls. Do birds get depressed??? so much to learn!