It appears you went offline without seeing my request for additional information. Because I don't want you to have to wait any longer, I'm going to answer as best I can without that information.
Just as with any other animal or human, lumps in parakeets have many potential causes. With a bump in this location, a problem with the crop is one possibility. Food is stored there, but sometimes doesn't pass through like it should. That results in a swelling that looks like a lump. If there's a bacterial infection of the crop, antibiotics would be needed. A fungal infection would require an antifungal. An impaction of the crop may need to be removed surgically.
The lump may also be an abscess. A pocket of infection can form because of a wound so tiny we don't even notice it to begin with. Abscesses need to be drained, then treated with antibiotics.
Unfortunately, parakeets are very prone to tumors, so there's a chance that's what it is. Tumors can be cancerous or benign. Parakeets have survived for lengthy times with non-cancerous tumors, and they can survive surgery for tumor removal. But so much depends on the type of tumor, how deep it goes, and whether it has spread (if cancerous).
With all these possibilities, you'll have to wait until your vet examines Pretty Bird. I know how worried you are, but there just isn't anything to do but wait at this point. If you have more questions, let me know in a REPLY. I'll be keeping you and Pretty Bird in my thoughts and hoping for the best possible outcome.
My goal is to provide you with excellent service – if you feel you have gotten anything less, please reply back, I am happy to address follow-up questions. Please remember to rate my service only after you have all the information you need. Thank you!