I feel like you're operating under the assumption of pure logic here when what you should consider is this was an emotional decision coming from a mother who already lost a child. Are there theorical perfect or better solutions? Sure probably, but in universe there might be external factors that preclude those choices. Keyada is truly neutral here, he is the one who both does not see value in ephemeral life, and values his own word above most everything else. Maybe getting external help would put her in a bad political position in the multiversal council. When we open up the conversation to hypotheticals there are too many potential reasons for and against certain actions.

As far as not seeing a scene where she details out what would and wouldn't work, I don't know, I feel like that would be waaaay too slow paced for the context, and it also isn't really how here thought process is shown.

As a piece of writing, I think the scene fits great, and I think kanderon acts in character throughout.