Hi There. My 13 Year Old Daughter Has What Looks

Hi there. My 13 year old daughter has what looks like a broken blood vessel under the skin on her lower lip. The colour is dark purple/black and it has definitely increased in size over the month or so. There has never been any external bleeding but she is growing increasingly conscious of it. Is there anything we can do to help treat it/get rid of it? Thanks in advance for any advice.