What name do you think suits a 1920's ballerina best. ?

I like Lenora and Marina the best. Marina sounds a bit modern though, whereas Lenora is more era-appropriate.

Is this for a gravestone? Because I don’t think there are any 1920 ballerinas alive

The name "Kalashnik" will inevitably make people think of the "Kalashnikov" assault rifles developed in the former Soviet Union. Do you really want a ballerina character whose name makes people think of assault rifles?  If you want to make her Ukrainian descent obvious, choose a name that's obviously Ukrainian, ie one that ends in -ko or - uk, like Kravchenko or Gavrilyuk or  Shevchenko or Savchenko.

As for McAlister, yes, there are Irish people with that surname, but it's originally Scottish. For a name that's clearly Irish go for O'Brien or Kelly or Sullivan or Doyle or Gallagher.

But look: there is no special name that particularly "suits" a 1920s ballerina. Call her Susan Smith or call her Natasha Romanova, it makes no difference.

I only like Ada or Juliet 

I like Ada the best.

Oop. Thank you Catherine I didn't know that. I pulled it from an Irish surname in page so I trusted it to be true.

Mc surnames and Alistair are Scottish in heritage. Not Irish.

Out of your options, the one that sounds like a 1920's name most, especially that sounds good going with Kalashnik McAlister is Inessa. I think "Inessa Kalashnik McAlister" sounds pretty good ;) Inessa sounds like a good 1920's name, plus sounds good with the rest! And I guess you're writing a story? :)

Mira Juliet Kalashnik McAlister