Did you handle everything perfectly with regards to xah ?
Yes/no
If no, why place that expectation on your daughters ?
Way I see it, you can either put it down to human frailty and move on or stay stuck in the mental anguish of why ? how ? why not ? etc.
They did what they thought was best at the time, with the knowledge they had at the time.
You carried on with xah at the time, doing what you thought was best at the time with the knowledge you had at the time.