In Marvel Comics, she becomes a hero in her own right and is now just about the right age to do that in the MCU.
We saw that Scott Lang’s daughter Cassie was not eliminated by Thanos’ snap. so she’s now five years older compared to all those who were brought back to life or stuck in the Quantum Realm.
In addition to the fact that old characters are moving away and letting characters that had been supporting heroes take the lead, there’s also the fact that, with the five year time jump that the MCU received in Endgame, the world looks like a very different place which also means entirely new young heroes.