I need advice about my mortgage

In a divorce, she would have no rights to it: as something you purchased pre-marriage, it is not marital prperty.
If you pass away while still married, she will be entitled to a share of your estate--so an interest in the house--even if you try to disinherit her or leave her only a small amount: without getting bogged down in the details (which vary by if you had a will no will; if you had children and how many; etc.), assume that she will get between a 1/3 and 1/2 interest in the house if you pass away before her while the two of you are still married. Your state (like many states) prohibits disinheriting a spouse and ensures by law they get part of what you leave behind. Any mortgage would still have to be paid off when you die, however, or else the lender can foreclose and whomever is inheriting the home (e.g. wife; wife plus your children) will lose it. The lender's right to be paid or foreclose supercedes inheritance rights.
There are ways to minimize your wife's interest in the home, or *possibly* protect it entirely by putting it in the right kind of trust (though putting property into a trust has it's own complications and downsides): if you want to keep the house as much as possible out of your wife's hands if you pass away before her, speak to a trusts and estate's attorney.