Lip blister

I was wondering if anyone else has a lip blister on their top lip. I'm not sure what the official name is for it or if there is an official name for it. I named it that. Both myself & my daughter have them on our top lip. I guess it makes us unique & something that only her & I have. A birth mark maybe? It's on our top lip in the middle & looks like a bubble. She was born with it & I guess I was. My hubby pointed it out to me 1 day. I never paid attention to it & thought it was normal. He's the 1 that made me realize that we both have them.