Why would a teenage girl with no prior military training or combat experience be leading a military unit? Concentration camp prisoners who escaped or were liberated by the allied advance wouldn't be in a physical condition to fight, the human body would need time to recover from being nearly starved to death, as well as fighting whatever diseases spread in the crowded, unsanitary conditions created by the nazis. Camp prisoners who were alive when the allies arrived could be gradually nursed back to health, but probably not on a timescale that would allow them to see combat in WW2.
The western allies might have been willing to endorse the creation of a Jewish military legion like they did in WW1 under Trumpeldor, but it wouldn't be involved in the capture of Berlin if it was formed by the allies. The Big 3 had agreed to let the Red Army take Berlin. Stalin's antisemitism and Marxist-Leninist ideology makes Soviet support for this hypothetical unit more or less impossible. OTL, the postwar USSR pretty much refused to recognize the disproportionate suffering of European Jews, to they point where they almost built a sports stadium on top of the Babi War massacre outside Kiev.
This belongs in the writers' forum.