Ukrainian 'Let It Go' Girl Sings National Anthem at Charity Concert

The little Ukrainian girl who won over hearts with her rendition of a "Frozen" song is on to bigger and better things -- and that would be her country's national anthem.

7-year-old Amelia Anisovych performed "Shche ne vmerla Ukrainy" Sunday night at the Atlas Arena in Poland, where they were holding a charity concert to further Ukrainian aid there.

As you can see, Anisovych's rendition was pretty stirring ... with the crowd cheering her on, and even holding up their phone lights in solidarity. She got a huge round of applause once she wrapped, and for good reason -- she was awesome!

The kid is famous for a now-viral video of her singing "Let It Go" from down in a bunker in Kyiv, where she and her family had been hiding out for several days as the city was under attack.

Although her parents stayed behind -- Amelia, thankfully, made it out okay and is now across the Polish border ... where it seems they've welcomed her with open arms and then some.

Considering how well she's done so far in her music career, ya gotta figure she might have a future in the biz once this is all settled.