"I am grateful to her for never forgetting her country. She inspires me. I also want to become a professional tennis player, glorify my country and be able to help those who need it."

Makar lives and trains in Ukraine, amid air raid alarms and Russian attacks.

"When the war started, it was tennis that kept us in shape," he says. "We couldn't focus on anything, we didn't know what would happen tomorrow, but I picked up my racket and played. It was in the game that I could forget about everything that was happening around me."

In November, the foundation wrapped up a series of tournaments for young tennis players in Ukraine. The winners received a grant from the foundation to support their tennis career.

But planning such an event comes with extra stress. The tournaments took place in locations with bomb shelters for the children to go to during air alerts.

Svitolina handed out prizes for the girls' event in a shelter as sirens blared outside. The group remained in the shelter for four hours until they were given the all clear to leave and start the boys' final.

But the main focus, as always with Svitolina, is bringing the children joy.

"The parents are happy that the kids are having fun and competing," Svitolina says.

The children also have access to a mental health specialist. And Elina also has an open-door policy when it comes to advice and questions.

"I talk with the kids at the beginning and they can ask me any question," she says. "There are some good questions. They always ask the toughest ones!

"It's a good opportunity for the kids to develop their talent but also get this opportunity to see the world as well."

Daria was one of the tournament winners, receiving a financial grant which she will spend on trips, competitions and new racquets.

"I and the other children had a lot of emotions from the training process but also from the fact that each of our lives had changed," she says.

"The war started and everyone was forced to leave their homes, adapt to new conditions. We haven't seen each other and competed against each other in such a long time."

Daria says she first met Svitolina when she was six or seven years old, travelling with her mother to get the tennis star's autograph at a Kyiv shopping centre.

"She is a real leader who defends Ukraine on all possible platforms and helps children who stayed and did not leave," Daria says.

The tournament also is an opportunity to develop tennis in the country. Ukraine's sporting locations have been heavily hit by shelling. More than 300 facilities have been destroyed, according to Vadym Gutzeit, Ukraine's Minister of Youth and Sports.

"The national centre for tennis has been destroyed and there are not many places where people can play tennis," says Svitolina.

"I feel like I have a mission for years to come to continue supporting tennis and to bring something new to Ukraine with tennis and with sport, because it is so important. Sport brings people together.

"I'm really thankful for the sport that I chose and for the opportunities that I've had in my career so I can pass this knowledge and this dream to the kids of Ukraine."