Joel Davila, 6, and his sister Alondra, 4, woke up on Monday at 5 a.m. They walked 40 minutes from the homeless shelter where they have been living in Hunts Point to see if they had won the lottery in the South Bronx -- a chance to attend a school built with them in mind.

The school, Children’s Aid College Prep, will open in late August. Run by the Children’s Aid Society, the new charter school is designed for children in particularly difficult circumstances, and will provide services like medical care, food, parent support and counseling.

Children’s Aid College Prep has a space in Morrisania and a new principal in place, and interviews for teachers are under way. All it needs are the children.

Like other charter schools with more applicants than seats, College Prep will determine its admissions by lottery. More than 500 applied for the 60 spots in kindergarten and 60 in first grade. But this lottery, which took place Monday morning, was slightly different, with extra weight given to children with high needs.

Joel was given an extra five chances -- called preferences -- in the lottery to win a spot at the school. Alondra was given four preferences, though she will automatically be admitted if her brother gets in.

“It’s important for them to get an education,” Michelle Davila, their mother, said through an interpreter. Ms. Davila moved to New York 16 years ago from Puerto Rico, and has been dependent on those around her because of her sixth grade education and lack of English. “So they don’t end up like me,” she said.

The Davila children received one of their extra preferences because they live at the Eddie Fernandez houses, a homeless shelter in Hunts Point. It’s an austere brown building with security cages in front and barbed wire around a playground. Living in District 12 brought them another preference.

Children’s Aid gave Joel and Alondra a third preference because their mother is a single parent. A fourth extra chance was given to Joel and Alondra because they don’t speak English.

Ms. Davila left the shelter early Monday morning to attend the lottery, though her presence was optional. This was important to her. Other parents will receive letters in the mail with their children’s lottery numbers.

Around 9 a.m. the two older children walked alongside her as she pushed a double-stroller with her two babies. They walked past the clank of bottle sorters, abandoned lots, shuttered businesses and cratered sidewalks decorated with glittering shards of glass.

In the lobby of the Children’s Aid Society’s Next Generation Center, a sleek and modern youth community center, a projector displayed a spreadsheet of all the applicants' names, with their lottery ranking. The lottery was run by an independent auditor, with random selection by computer.

Only a handful of parents had shown up. Children’s Aid had downplayed the importance of parents' attendance, because charter school lotteries are notoriously emotional.

“We wanted to avoid that,” said Anthony Ramos, a spokesman for Children’s Aid.

Alondra is spunky and likes to swing upside down in the arms of her social worker, Veronica Melendez. It was Ms. Melendez who told Ms. Davila about the new school and helped her apply online. Joel has brooding eyes and a somber gaze that is unsettling for a 6-year-old. He clings to his mother. Joel likes to paint by numbers, but it’s words he wants to study.

“I want to learn how to write letters and learn the alphabet,” Joel said through an interpreter.

Joel also has not attended full day kindergarten, which is another reason he will need extra help and why he received his fifth extra chance.

After 11 a.m., Ms. Davila couldn’t wait longer and whisked her two infants off to change their diapers. Parents and children lined-up to find out their lottery number from a staff member. Ms. Melendez walked with Joel and Alondra as each stepped up and said their names. Joel was No. 67 and Alondra No. 103.

Because of their low numbers, both children will likely attend Children’s Aid College Prep in the fall. There were 1,012 names in the lottery, because of all the extra entries for preferences. Joel and Alondra’s numbers will be even lower once the duplicate numbers are weeded out and the final assignments are made.

Still, Alondra and Joel were disappointed. They thought school started today. On the long walk home, Alondra told Ms. Melendez she wants a pink backpack for school.

Ms. Melendez smiled and said she promised to get one for Alondra through Children’s Aid, along with school supplies.

“I’m excited because the teachers will have everything,” Alondra said. “Like juice, food and toys.”