Thank you for your query
The soft swelling can be a lot many things. If she had a minor trauma, it can result in such a swelling. Sometimes some benign exostosis
(bony overgrowth) can also be painful. Depending on your locality it may be a tubercular infection
. And very rarely it can be small tumor
. Fortunately all of them are curable. Some heal fast, some take longer time. But for now, apply some cold
compresses over the swelling. Some analgesics will also help. Further tests like X Rays will be required before you doctor comes to a final diagnosis. But you need not be anxious.
Hope that helps
God bless you