Even if she did gain some confidence in herself and feel like she had grown by quite a lot, she did not believe herself to be ready to face any of them alone.
The same could be said when it came to others evaluating her capabilities.
They would have to judge her based on what she showed and how she performed in many different types of situations, similar to those, to know that she would be ready to handle that kind of danger.
Ash knew that more than anyone, as she was always underestimating her own capabilities and overestimating her opponents' capabilities.
That was why she had stuck to performing whatever role she had to perform as a part of the group for so long during the fight with Black Avalanche.
She knew that Black Avalanche was a step up in terms of difficulty compared to Nightstalker and Ironhide.
With it being more dangerous than them, she knew that she could not bring it down on her own.
