(CNN) A mother sat in an office at the Consulate General of Mexico in Atlanta. Her name was called and she quickly rose to receive the document she came for on an early morning, the one that makes her 5-year-old, US-born daughter a dual citizen.

Five Mexican consulates across the United States told CNN they've seen a rise in applications for dual citizenship in recent months, including for US-born children. The increase seen at the consulates comes as a wave of recent deportation cases have made national headlines and fear has spread among undocumented immigrants. Parents are fearing the worst: being separated from their children.

Sofia Garcia Ceja, who leads the registration department in Atlanta, said parents are "anticipating a possible return to Mexico."

"It used to be they came to register one kid or two. Now they come with all of their children," said Garcia, who's been working with the Mexican Foreign Service for over 30 years.

The Atlanta mother of three said she and her husband, who's also Mexican and lives in the United States illegally, have planned to ask a close relative to take care of their daughters if they both get deported. "I'm doing it as precaution, so in case we go back my daughter can have access to school and health care," said the woman, who didn't want to give her name because of her undocumented status.

She has also had conversations with her oldest daughters, ages 8 and 11, about a possible move to Mexico if she or her husband are removed from the United States.

"I want them to be aware but not scare them."

Preparing for the worst

Javier Diaz de Leon, consul general in Atlanta, said dual citizenship serves as "the most essential form of protection for binational families."

Diaz said that if the US-born child of a Mexican has dual citizenship, that allows the consulate to work with local authorities to get the family reunited in Mexico in case the parent is deported. And while under Mexican law minors cannot be deprived of their rights to education and health care, a dual citizenship gives children immediate access in both places.

Birth registrations in Atlanta 2016

January: 88

February: 120 2017

January: 257

February: 230 Source: Consulate General of Mexico in Atlanta

The Atlanta consulate processed 257 applications for dual citizenship in January and 230 in February and has no more appointments available for the rest of March and April. The number of dual citizenship applications processed for January and February of last year was 88 and 120, respectively.

An American-born child of a Mexican national becomes a dual citizen through a process called "registro de nacimiento," or birth registration, according to Mexican law. In the United States, consulates issue a certified document establishing dual citizenship.

In 2016, the Atlanta consulate issued 1,795 dual citizenship applications. This number is in line with the yearly numbers of birth registrations issued during President Obama's second term, which ranged from 1,538 to 2,272. CNN reached out to the Mexican Embassy in Washington for national numbers on dual citizenship issued this year, but data was not yet available.

New administration, new fears

The recent surge in applications for dual citizenship in San Francisco, Philadelphia, Atlanta, Miami and New York coincided with the transition of power in the White House, and even the outcome of the November election for some consulates.

Birth registrations in San Francisco 2016

January: 10

February: 36 2017

January: 66

February: 94 Source: Consulate General of Mexico in San Francisco

The San Francisco consulate processed 28 applications in November. That number almost doubled to 53 applications in December. In January, the number went up to 66 and in February, the consulate processed 94 applications.

Consul General Gemi Gonzalez Lopez said some parents come to the consulate with concerns -- and misinformation -- even believing they won't be able to send for their children if the family is separated.

Gonzalez reiterated this is false. The same process to obtain dual citizenship can be done in Mexico and takes about two weeks, depending on the state.

But Gonzalez added, "If a family, for one reason or another, moves back to Mexico, the children [with dual citizenship] would enter Mexican territory as Mexican citizens, not foreigners."

Miami has also seen an increase in the number of dual citizenship applications and has a wait list of about a month and a half for an appointment.

Angela Martinez recently visited the Miami consulate to obtain dual citizenship for her toddler.

"We're preparing more than anything, in case my husband and I get deported," she told CNN's Jose Manuel Rodriguez. "We want to have the paperwork ready so [my daughter] could be sent to our country."

Plan B and C

Dual citizenship is not the only step undocumented parents are taking to protect their children in case of a family separation. Some parents are also drafting documents to give temporary custody to someone they trust, according to consulates CNN reached out to.

People wait in line at the Consulate of Mexico in Miami earlier this month.

Such is the case for a mother of three from Chattanooga, Tennessee. The woman, who also didn't want to give her name because of her undocumented status, said she and her husband have documents ready entrusting their children, ages 9, 12 and 15, to a relative in case they're both removed from the country. But the woman said that ultimately, "the kids would move to Mexico with us."

"The younger ones say they want to come with me, but the oldest wants to stay because she wants to study in the US," she said.

Consulates adjust to the high demand

In Philadelphia, the consulate is opening some Saturdays to keep up with requests. Activity in the consulate related to dual citizenship for children has more than doubled from eight appointments a day to more than 24 in recent months, according to Alicia Kerber, consul general of Mexico in Philadelphia.

"I think people are really concerned about the situation," Kerber said. "[Parents] are afraid of going to a park, or a movie, or the school with their kids."

Consulates are also issuing dual citizenship on the road. New York has a "mobile consulate" that travels around the tri-state area. Combined with the work done at the office in Manhattan, they've been issuing around 50 a day in the last three months -- a 30% increase from previous months, said press officer Carlos Gerardo Izzo.

But the biggest challenge consulates face is educating the community they serve. "Before it was common for people to come with an appointment to issue a passport. Now they're coming for legal advice," said Diaz, the consul in the Atlanta office.

"We have a community that's very scared, very distressed, and very uninformed."