How do I keep my kids from my first marriage from being disinherited by my new spouse?

This is the classic blended-family risk. If you leave everything outright to your new spouse, they can later change their will and leave nothing to your children. A common solution is a QTIP trust (qualified terminable interest property): it provides income and support for your surviving spouse during their lifetime, then passes the remaining principal to your children when the spouse dies.

Other tools include leaving specific assets directly to your kids, using life insurance to fund their inheritance separately, or a prenuptial agreement clarifying separate property. Also review beneficiary designations, since a new spouse often becomes the default beneficiary on retirement accounts. Blended-family planning is nuanced, so work with an estate attorney and revisit it after remarriage.