* The three are beyond human comprehension: They are celestial beings, possessing wisdom and powers far beyond human understanding. Their appearance and nature are quite strange, making it difficult for a young girl to explain their essence to another being.
* Aunt Beast is a different species: Aunt Beast is a creature from a different planet, with a unique perspective and communication style. She relies on feelings and intuition rather than logic and language, making it difficult for Meg to articulate complex concepts.
* The three's true nature is hidden: The three are disguised as ordinary people, their true forms and powers veiled. Meg herself doesn't fully understand their capabilities, making it hard for her to convey the vastness of their being.
* Meg's own confusion and fear: Meg is a young girl grappling with a confusing and terrifying situation. She is overwhelmed by the vastness of space and time, and her own emotions can make it difficult for her to explain clearly what she is experiencing.
Ultimately, Meg's struggles reflect the inherent limitations of human language and understanding when trying to grasp the truly extraordinary. It is a testament to the power of faith, intuition, and the bonds of love that Meg manages to connect with Aunt Beast, even without fully explaining the three.