When Russia invaded her country, Veronica Ahafonova played piano to drown out the sound of the explosions.

We first met the teenager in March when she and her mother were fleeing Kharkiv as refugees, leaving behind everything they knew. They were living in the dark in an overcrowded motel with the curtains shut tight in the hope that Russian bomber planes wouldn't see the building.

Like millions of Ukrainian children, Veronica's life changed forever when this war began.

Nika, as she likes to be known, told me then that she woke each day amazed that she and her family were still alive: stark words from a 15-year-old. She described rushing to a cramped, cold basement whenever the sirens howled to warn of a Russian attack, and called what she'd been through "very traumatising".

Ten months on, Nika is living in the UK and says she's finally able to sleep soundly again.

"I needed time to understand that now I'm in a safe place," she said, when we met up recently in England.

She's staying with a host family and studying for free at the prestigious Charterhouse school, where she's thriving. She now plays piano only for pleasure.

"I don't have air alarms every hour and I don't need to think about what if the next second a bomb is going to be near me," Nika says, although she still jumps when a door slams or there's fireworks.

"I don't think it will ever leave me because it's in my mind. But I hope it will."

Kharkiv, Nika's hometown, is close to Ukraine's northern border with Russia and was heavily shelled for months until Russian troops were forced out of the region in September.

Today, the suburb of Saltyvka is lined with the blackened ruins of giant apartment blocks, but in the city centre the rubble and shattered glass we found in March after multiple missile strikes have been cleared away.

Patriotic billboards all over town declare that "Kharkiv is working!" and the metro, where we last saw whole families sleeping on platforms and curled up inside train carriages, is now running again.

But residents are coping with a new problem: no electricity, heat or water for many hours at a time, as Russia targets Ukraine's power supply with its missiles in the middle of winter.

Only eight of Nika's 28 classmates are still in Kharkiv and they study remotely these days for safety. But their teacher, Maria, never left. She conducts classes online for students scattered all over the country and even abroad.

If the power goes, she switches to using the internet from her mobile phone, lights a candle, then carries on.

"Russia just doesn't know who we are. We're strong, we'll get through this," Maria tells me, although she becomes tearful talking about the pupils. "I just want to hug them," she admits.

Nika misses her old teacher, too, as well as her Ukrainian friends who went through the same panic-filled days she remembers.

"You can be in the middle of attention [in England], but you are alone, because nobody here understands what I experienced and I hope they never will," Nika explains.

"Sometimes I want to talk to them about that," she confides. "But I understand if I tell them everything it may be uncomfortable for them."

Her mother, Natalia, tells me Nika is coping "amazingly well" and that school in the UK is the ideal distraction from thoughts of the ongoing war and destruction at home.

Natalia, on the other hand, still has the air-raid app on her phone and can't stop checking for news from Ukraine, not least because her own mother stayed behind in Kharkiv.

Nika's grandmother Tamara now lives in the dark for much of the day. The lift in her block of flats no longer works and even when the blackouts end, she tries to use minimal power to conserve it.

Like many older people, she didn't want to leave because "home is home" but when we went to see her, she said she felt like she was "living on a powder keg".

"It's really affecting my nerves," she says. "But then I tell myself to get a grip, that it won't be for long. My girls will be back soon," Tamara tells me. "I live for that moment, though I'm so happy that they are safe."

The day we dropped in was Nika's 16th birthday, the first year she and her grandmother have been apart.

"She's so grown up!" Tamara smiles, when she puts the phone down after congratulating her granddaughter, then starts to cry.

"What have they done to us and what for?" she wants to know. She means the Russians.

In England, Nika isn't thinking about the future, for now.

"I want my home back, my previous life back, but I know it's not possible. So maybe I want stability and calmness. To build my life here for now. To be a teenager," she describes her greatest wish.

"I would like peace and calm in Ukraine and for people to stop dying."

With Tony Brown, Matthew Goddard and Hanna Chornous

(editor-in-charge：Press center4)