HOUSTON — Knatalye Hope and Adeline Faith Mata, conjoined twin girls who were separated in 2015, started Pre-K this week.

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The girls, who were born in 2014, underwent surgery the following year at Texas Children’s Hospital. Doctors had to separate Knatalye and Adeline from the chest wall, lungs, pericardial sac (the lining of the heart), diaphragm, liver, intestines, colon and pelvis. It took doctors roughly 18 hours to separate the two, while doctors worked on Knatalye for 23 hours and 26 on Adeline.

Today, they’re happy and healthy and Pre-K students who love school, especially recess, according to their mother, Elysse Mata. She said the girls are looking forward to taking the bus to school starting next week.