Spot on DD's lip

[fitflop]

Does anyone have any idea what this could be on my DD's lip?
She's had it around 6 weeks.

It looks like a bit like a blood blister under her skin.

My ds had a few of these on his lip. They started protruding and aching. GP referred him to local hospital to have them zapped by laser.

It worked and they disappeared within two weeks.

Was just about to say what fliss said, my youngest had something similar and had it zapped with lasers at the hospital. Dr said it was a bit like a hernia but nothing at all to worry about but better to sort it asap as the older they are the harder it is to get funding for the treatment.

Thanks very much.
I must admit I was starting to get a bit worried.