Thank you for the photos. Sorry Jade is having this issue. It looks like a either an abscess (infection), a cyst or a tumor. It does not appear to be an injury. I cannot tell you much on how to treat it without knowing what it is. I strongly suggest you take her to a reptile veterinarian for an exam. They will likely do an aspirate of that lump to collect some cells and get a diagnosis. It if is an abscess she will need antibiotics. If it is cyst or tumor it will likely need to be removed with surgery or it will never go away.