The fighting skills she got from them was the best ones

The kids couldn't even retort when Axel had already left and so Maya told them: "Do your best, fight like one, and protect each other."

Maya then got up and the kids got ready, she then joined Peter, while Axel and Kevin went to place themselves around the arena to be able to intervene rapidly if something went wrong, and only then did Maya motioned for Peter to start the countdown.

Willow could only use a small part of her powers, and she was sure that her Dad wanted to test her.

Those vines weren't powerful enough to harm her and it was a friendly fight, so it was the perfect opportunity to check if she was able to use all the fighting techniques she had assimilated thanks to the knowledge she had obtained through her bloodline, and those that she had learned from them.