"Just a walk," he answers, looking at Vanya with a barely restrained expression of amusement. "Are you expecting me to scold you?"

It seems as though she is. Obi-Wan is not the right man for it, certainly not in this situation and maybe not at all. While he is happy to offer guidance and advice, he failed his own Padawan to the extent that undid the entire Galactic Senate, undid the democracy they had been working so hard to protect. Anakin's powers are ones Obi-Wan understands completely and still he had failed.

He won't presume to be the one scolding Vanya for using powers he can't possibly begin to wrap his mind around.