For sure girl?? 16 wks 6 days

Hi so I got an ultrasound done for the gender reveal, I had twin boys the first time. This time she says baby is a girl! I guess I'm just confused what I'm looking at lol I don't see 3 lines like everyone says, I'm 16 weeks 6 days in this scan. Baby kept wiggling 🤣( this is between the leg shot in case that's not obvious )