What do I think twins boy or girl

My friend is 35weeks 28th a girl and she went in for an ultrasound because she was having contractions the baby weighed 6lbs 2 oz and meausuring her belly she's 4weeks ahead. Well they to down to the pee pee and it's a boy. So she comes over and we use the fetal doppler and hear two different heart beats one down low under belly button and one up high by rib cage. The one low was 122bpm the one high was 136 also she found out at 20 weeks it was a girl