LOS ANGELES (KABC) -- Formerly conjoined twins, affectionately known as the "Two Marias," are about to celebrate an important milestone - their quinceanera.
Nearly 15 years ago, we first introduced you to the two infant sisters conjoined at the head.
Through the years, we've documented their medical progress and their birthday celebrations, but on Aug. 8, the twins are celebrating their 15th birthday with a quinceanera.
Doctors say not only is it rare to see twins conjoined at the head, it's even more rare to have surgery to separate them and incredibly rare to have them both survive.
At Children's Hospital Los Angeles, friends and family sang "Happy Birthday" to Maria Jesus Hull, nicknamed Josie, and her sister Maria Teresa Cajas, as part of a party preview.
"I can't wait to celebrate with everyone," Josie said.
It's a momentous occasion and a medical milestone.
"We've heard that no conjoined twins that were joined at the head have actually made it to age 15," said Josie's adoptive mother, Jenny Hull.
In 2002, the organization Mending Kids discovered them in a small village in Guatemala.
Through the generosity of many, they traveled to UCLA, where they underwent complicated and risky marathon surgery to separate their skulls and their brains.
CHLA's Chief of Neurosurgery, Dr. Mark Krieger said the biggest concern when separating craniopagus twins, which are twins conjoined at the head, is the blood vessels.
During the procedure, Josie's brain did not get enough blood, and she suffered a stroke. Teresa endured a brain infection afterward. Despite these setbacks, the two girls fought back.
"Teresa has had a harder time with it, but her family's love has gotten her through it and the support of Josie also. It's great to see them together," Krieger said.
Through the years, the two have thrived.
Josie is a 9th-grader in La Canada-Flintridge. Because of her care at Children's Hospital Los Angeles, she's a regular volunteer who brightens up patient rooms.
"I really like to decorate with my mom and my friends and make kids happy," Josie explained.
Siena Dancsecs, one of Josie's best friends, described her as a ray of sunshine who makes everyone happy.
"Nothing gets her down. She is never upset no matter what is going on," Dancsecs said.
Teresa lives with the Cajas family in Santa Clarita, where she provides constant cheer and inspiration.
The twins' medical needs keep them in Los Angeles, but every Sunday they talk to their biological parents in Guatemala. They plan to share the occasion via Skype.
"I can't wait for my party," Josie said, laughing.
It's Josie and Teresa's party, but their friends say it's also a celebration of the community that continues to open its heart to the "Two Marias."
Their quinceanera will be held at the South Park Center in downtown Los Angeles on Sunday. Four hundred guests are expected to attend.