Was the seven-time Istikhara prayer—due to an unwillingness to undergo a LASIK procedure after initial consent—justified?

If myopia causes harm, then it is a disease that must be treated, based on the Prophet's (peace be upon him) saying: "Treat yourselves, O servants of Allah, for Allah Almighty has not created a disease without also creating a cure for it." And based on his saying: "There shall be no harm nor reciprocating harm." And from the jurisprudential maxims: "Harm is to be removed." Therefore, istikhara (prayer for guidance) is not to be sought here, because istikhara is for matters where the correct path is unknown.

However, if myopia is something minor that does not result in harm, then istikhara is a Sunnah (recommended act), and whatever is good is what should be done after it. The mother should be persuaded kindly to gain her consent, and there is no harm in repeating istikhara if the correct path is not clear.