"Mum didn't know I was here for a long time," the young woman told AFP, seated next to her father, Ivan Synchin, on a bench in Druzhkivka, where she treats wounded fighters.

"We didn't say anything at first so she wouldn't cry."

But, she said, her mother was calmer knowing the pair were near each other, even after Russia launched its full-scale invasion in February last year.

The war sparked a mass rallying of Ukrainian forces, often including two generations of the same family.

Marta joined the military seven months before Moscow sent in its troops. The country's east was already gripped by conflict, but at the time she saw only a few wounded per month. Now, she treats countless more.

She had followed her father into the military after initially taking her mother's lead into medicine, training as a midwife.

"Before, my work was about the start of life, and now it is about saving life," she said, tucking her hands into her camouflage jacket against the cold.

While Ivan and his wife were proud of their daughter, he said he did not think she would accept having their nearly 18-year-old son also join the armed forces.

"There are already too many of us in the military," said the 48-year-old, who has served more than seven years and whose brother also volunteered to fight after the February invasion.

- 'They died together' -

Marta had not seen her mother or brother for nearly a year since the war started, but sporadic visits with her father keep both their spirits up.

Each time, Ivan said, he is grateful that "we're together, for now".

Marta said she knew of several relatives serving: A father and son at the front, a mother and two sons working as drivers, and another nurse whose father and brother are in the infantry battalion of their brigade.

The list is emblematic of how the war has extended its deadly reach into the heart of Ukraine, leaving few untouched by loss as a mounting toll of coffins are sent home from the front.

Oleg Khomyuk, 52, and his 25-year-old son Mykyta volunteered for the army together shortly after the invasion. Not long after its first anniversary on February 24, both were killed in a trench near the embattled city of Bakhmut.

Khomyuk covered his son with his body during an attack but a shell exploded nearby, killing them both, said Yuriy Samson, Oleg's brother, at their funeral in Kyiv.

The Ukrainian defence ministry posted a photo on Twitter of the pair side by side in fatigues, cradling rifles.

"They died together," the ministry wrote.

- 'A certain peace' -

It's a fate Volodymyr Chaikovsky, 54, tries not to dwell on. He serves in the same brigade as his 25-year-old son, also named Volodymyr.

"Of course I worry about my son," he said, seated next to the younger man at the dust-covered patio table of an abandoned home not far from the front lines near Lyman.

"But he is experienced," he said. "And after all, everything depends primarily on you and your training, then it's a matter of military luck."

With years of service under his belt, Chaikovsky was called up on his son's birthday in 2015 -- 20 years after he had first been discharged -- to fight Moscow-backed separatists.

Last year, he returned as a commander in a tank battalion.

He and his son marked his birthday this year near the front, stealing a moment away from the battlefields to share a coffee.

"It's not really about celebrating, the main thing is to see each other, not to be soldiers for a while, just to talk about civilian things," he said.

The younger Chaikovsky said being in the same brigade "adds a certain peace", since they know where the other is and what the situation on the ground is like.

He hasn't shaved his beard since the debut of the invasion, he said, laughing in front of a basketball hoop in the overgrown yard as dogs barked nearby and explosions rumbled in the distance -- and doesn't plan to until the war is over.

"I don't know how much longer this will last," his father said. "But we have to end it once and for all, so no problems are left for my youngest son."