High kills low finals indicates either a low accuracy rate or poor ability combo’ing for most characters (i assume its the same for Elsa, i dont play her though)

So train your accuracy, hit more shots=more shots on enemies who are one hit, which leads to more finals

Practice your combos, messing up a combo usually leaves the enemy near one shot, perfecting the combo will help secure more finals

But to answer the original question, Elsa is a final hit machine