– The migrant caravan came alive one morning last week with a rustle of plastic tarps being taken down and packed. A crowd gathered well before dawn.

Near the back of that crowd stood Keila Savioll Mejia. Two weeks earlier, the shy 21-year-old had left home in Honduras to join the caravan with her 2-year-old and 4-year-old daughters. She listened as organizers announced that two trucks were available to take women and children from Tapanatepec to the next stop, 33 miles away.

Mejia thought about rushing forward to claim the last spot. Both of her daughters were sick and Camila, the oldest, was tired of walking. But she said she worried they would be crushed or suffocated in the throng.

"There are no more trucks," an organizer said over a loudspeaker. "Let's go." And with that, Mejia and her daughters set off on foot.

President Donald Trump has portrayed the migrant caravan as a monolithic threat, a mass of "terrorists" intent on "invading" the United States. In reality, the caravan is a collection of individuals and families, and few were worse off than Mejia.

As she carried 2-year-old Samantha through the streets of Tapanatepec, she saw several families with sturdy strollers they had bought for 900 pesos — around $45 — at the Mexico-Guatemala border. Mejia had nothing, not even a baby carrier.

By the time the caravan reached the edge of town, Mejia's thin arms already ached from carrying her toddler. So mother and daughters rested under a tree.

Mejia wore pink plastic slippers; the girls wore sandals that were hardly any better. Besides a few donated diapers friends carried for them, all their belongings fit into a tiny "Mafalda" bag on Mejia's back.

Soon, they were back on their feet, Samantha on Mejia's shoulders and Camila walking.

As they walked through the predawn darkness, the silence was broken every few minutes by the buzz of approaching motorcycle taxis. The tiny three-wheel vehicles would pull up, and half a dozen migrants would pile in, paying a few Mexican pesos to get a little closer to the next stop. But Mejia didn't have a few pesos.

In Peña Blanca she had made 100 lempiras — about $4 — a day selling tortillas. When she heard of the caravan forming in San Pedro Sula just 50 miles away, Mejia borrowed 500 lempiras from a friend, packed her daughter's backpack and boarded a bus to the capital. By the time they caught up to the caravan a few days later, Mejia had spent half her money on bus fare. She quickly used the rest to buy food for the girls. "We've had to walk ever since," she said.

As young men strode past and another overloaded mototaxi sped away, an organizer issued a warning to those falling behind.

"Hurry up," he said, "or immigration will grab you."

Camila, her tiny legs already exhausted, collapsed to the ground. The girl closed her eyes.

"Camila!" Mejia said sharply.

Strangers stopped to offer to carry Camila, but the girl refused to let anyone touch her.

Minutes passed as Samantha cried and Camila screamed and the caravan kept going without them. Friends disappeared into the distance.

So Mejia did the only thing she could: She lifted both girls — one over each shoulder — and started walking.