Dayana Yastremskas has wrapped herself in the Ukranian flag before and after her matches since Russia's invasion of her homelandStadium Court Six at Indian Wells will on Friday play host to two Ukrainian sisters, who escaped from Odessa when the bombs started falling.
The Yastremskas went first to Lyon, where Dayana finished runner-up in the singles, and Ivanna made her WTA debut alongside her sister in the doubles.
Now in California, the sisters are pairing up again to play Irina Camelia-Begu and Monica Niculescu of Romania.
"I would say we are more like friends," Dayana told BBC Sport.
Dayana is 21, but Ivanna is just 15. So the older sister has had to take on some parental responsibilities as well.
"Before, I don't remember when we were spending that much time together, or travelling together, and it's a pretty high responsibility on me now," she added.
"I'm trying my best. I'm trying to make some fun so she can feel pretty relaxed. She looks very tall and big, but inside she is very small and she misses her parents.
"When I lost the final in Lyon we went back to the room - she started to cry and saying I want to go home, I want to see the parents. And I felt also very bad and I had to try and calm her down."
When the Russian invasion of Ukraine began, the sisters spent two nights sheltering with their parents in an underground car park in Odessa, a southwestern city on the Black Sea.
Their father decided they should leave the country as soon as possible, and so they made their way to the Romanian border on the Danube river with their mother.
Mum, though, had decided she should return to be with her husband, and so the sisters travelled on without her to Lyon to compete on the WTA Tour.
It is not always easy for them to speak to their parents as the internet is intermittent, and they are spending some of their time sheltering beneath ground. But at least there is so far no damage to the family home.
"We are living somewhere on the side of Odessa, where usually now they are not putting bombs, rockets and shooting," Dayana explained.
"Our house is near the sea and for now this part of Odessa is not destroyed. But it's kind of dangerous because our house is kind of high and it's one of the best apartments in Odessa. And we are also living pretty high on floor 12."
Dayana now walks onto court with the Ukrainian flag draped around her shoulders. She did so in Lyon, where only Zhang Shuai could stop her in the final, and then again in Indian Wells on Wednesday when she lost a tight three-set match to Caroline Garcia.
"When we arrived to Lyon, I understood that I have to play good. I have to play not only for myself but at least for my country because if you play good you have more opportunity to talk about your story, and Ukraine, and more people can hear you," Dayana continued.
"I try not to put together people and their personality with their politics. So when I meet the Russian players, I stay the same with them.
"It's nothing about exactly them, and they are supporting and asking 'How's your family?' I think they kind of understand what is going on. I'm OK with everybody."
Yastremska is currently just outside the world's top 100, but has won three WTA titles and been as high as 21 in the rankings.
She missed the first six months of last year after testing positive for an anabolic agent. The ban was later lifted by an independent tribunal which accepted the positive test had been contaminated.
So she has a career to think about, at a time when all her thoughts are with family and friends still in Ukraine.
Dayana and Ivanna will stick together. They plan to move on to Miami next, and then possibly to Bogota or Istanbul.
"I'm not sure if we are going to be back to Ukraine," Dayana said at the end of our conversation.
"If the war is going to stop, then we will go to see the family. If not, then we are going to fly from one tournament to another tournament."
