Cyst/abscess/tumor

[Laurenbusk]

Help! My chicks are 4-5weeks old and my olive egger (who is ridiculously smaller than the rest... we think she’s a bantam of sorts) has a huge hard clearish lump on her lower back.... it is rock solid and doesn’t move. I’m a first timer here and have no idea what to do. She’s eating and drinking and behaving just fine.

 

[Stipenvlerk]

Does she poop normally?

 

[Lemon-Drop]

Pictures would be very helpful.