They draw curious stares whenever they go out in public.

As quadruplets, Casey, Kelly, Rachel, and Erin Murphy are accustomed to the attention. Two are identical and the other two are strikingly close in resemblance, making it challenging for most people to tell them apart.

These days, the 18-year-olds from Swedesboro share something else: They are pursuing careers in medicine, like their late mother, Toni, an ob-gyn nurse who died in 2001 when the babies she desperately wanted were barely 2 years old. Their father, Michael, raised the girls alone, along with their older sister, Lyn.

Casey, Kelly, and Rachel are freshman nursing majors at Rutgers School of Nursing in Camden.  Erin is an animal-science major at Oklahoma State University. It is the first time that the four have been separated. The three stay in close touch with Erin, chatting through social media.

"I have to make a name for myself, rather than being known as one of the quadruplets," Erin said. "It's definitely a big change."

The trio have the same full-time academic schedule. They commute from their Gloucester County home, taking turns driving. They study together for tests but exhibit the same competitive streak they had when they played intramural soccer and made up nearly a third of the team.

"When we get the grades, we're always anxious to see who got the highest,"  Rachel said during an interview Monday at the Nursing School in downtown Camden.

Rachel usually leads the pack, "but we're not far off from each other," Kelly said. The sisters graduated in June from Kingsway Regional in Swedesboro.

The sisters wanted to follow in the footsteps of their mother, whom they have learned about through stories from their father and relatives. Toni Murphy was 36 when she died from complications from an infection. An RN, she worked for the doctor who delivered the quadruplets and previously was an elementary-school and prison nurse.

Each has different medical aspirations. Kelly wants to be a trauma flight nurse or possibly a nurse anesthetist, Kelly a pediatric oncology nurse, and Casey a cardiac, or possibly pediatric oncology, nurse.  Erin, an animal lover, plans to remain in Oklahoma and attend graduate school to become a veterinarian. Their older sister, Lyn, 31, is an X-ray technician for MedExpress and Crozer-Chester Medical Center.

"I always told them stories about their mom," said Michael Murphy, 52,  a boiler inspector for an insurance company. "I'm very proud that they are doing this."

The couple met in 1985. Michael was working at Hope Creek Nuclear Plant in Salem County and Toni was a college nursing student. They married the following year, and had their first daughter.

After Michael enlisted in the Navy, the young family moved around the country. He worked on nuclear submarines.

While living in Orlando, Fla., the couple decided in 1998 to have another child, using in vitro fertilization after several unsuccessful attempts to get pregnant. Three embryos were implanted and they anxiously waited.

"We were hoping for two or three. We were ready to settle for one," he said.

Murphy said the couple, then 33, were ecstatic to learn that Toni was carrying twins. Then an ultrasound revealed three fetuses.

"We were like, 'Oh my God!' " Murphy recalled.

Almost three months later, another bombshell: quadruplets.

"I was as white as my uniform," Murphy said with a laugh.

The quadruplets were born Nov. 3, 1998, prematurely at 31 weeks, common for multiple births. Casey, the smallest, weighed 2 pounds, 9 ounces, and Rachel, the biggest, was 3 pounds, 6 ounces.

The chance of having quadruplets without fertility drugs is one in 571,787, according to the Centers for Disease Control and Prevention. In 2015, there were 228 sets of quadruplets born in the United States.

With five children, Toni became a stay-at-home mother. Volunteers came to help with the quads' frantic feeding schedule. In the first year, quadruplets go through 9,068 diaper changes, 1,000 diaper wipes, and 8,840 feedings, according to

To tell them apart, their father had the girls' ears pierced with different-colored earrings. Kelly had pink, Rachel green, Casey blue, and Erin yellow.

"I still love blue," laughed Casey, who was wearing cornflower blue polish on her neatly manicured nails.

Less than a month after Michael and Toni celebrated their 15th wedding anniversary, Toni died from an infection. Michael returned to South Jersey to raise their children with help from his mother and in-laws. The quads were still in diapers and Lyn was just 14. He returned to civilian life after retiring from the Navy in 2005 as a machinist mate chief petty officer.

"I made a pact that I wouldn't let Toni down raising the girls," Murphy said. "I did the best I could do."

At a young age, the sisters were assigned household chores and expected to maintain good grades. When they got older, they landed part-time jobs to pay for extras. Big sister Lyn was always nearby for nurturing and hair and makeup tips, but Michael always attended school events and sporting activities.

With Erin out of state, the trio spend most of their time together, whether at school or working at Latteria, an ice cream shop near the home that they share with their father and two boxers, Chloe and Zeus.

"We're all going through the same stuff at the same time," Casey said. "We can help each other out."

There are differences among the petite blondes. Rachel is slightly taller at 5-foot-2; Casey the shortest at 4-foot-11. Rachel loves rap music, while Casey and Kelly are more fond of R&B and pop. Erin loves country music. Each has her own friends, too.

The sisters say college will prepare them for eventually living apart, although the bond will remain forever.

"We can't forever be known as the quadruplets," said Kelly. "We have to establish ourselves and be independent. Each one of us intends to do that in our own unique way."