The short answer is that most taxable distributions from inherited IRAs are taxed at the the child / beneficiary’s income tax rate. The longer answer is that there are multiple chances for inheritance to be taxed.
An important part of the family’s emergency plan is to make sure you have a plan for when the financial spouse can no longer serve the family in that way, either because they are no longer interested or because of their incapacity.
Tax planning is very different than tax return preparation. The goal of tax preparation is to minimize your tax owed this year. The goal of tax planning is to maximize your after-tax net worth by minimizing your taxes owed over your lifetime.