Devi Sandhay and Chaya both looked at Karna and were unsure whether to be concerned or proud. There were two great revered sages fighting to get the right over who would become the Guru of their son. That is a proud thing.
But they are also concern, If Karna is too strong he will attract the attention of those who should not be named.
If the king of Deva found this he would definitely do anything in his power to make Karna either weak or worse make him suffer curses through the hooks and crooks.
Indra already did it many times and he will not shy away from doing it again especially after the unknown terrifying power they felt before.
Gandhari on other hand was confused, She didn't understand why they two were fighting over? Didn't the one of the conditions Karna spoke of yesterday was that he should get the right to learn from many teachers.