I suggest you talk with a lawyer that is knowledgeable in estates, trusts, and wills. Generally, a will does not come into play until the person has passed away. (There are exceptions) So if the home is sold before she passes, you may risk having more than tax consequences to deal with.
On the tax front, if the property is sold before she passes and before the property is passed to you, then the gain is figured on the original cost basis established by your mother's ownership, and your mother will pay taxes due on the gain (if any taxes are in fact due.)
If the property is sold after it's put in her estate (which is generally not established until after she passes), or after the property is passed to the named beneficiary(s) in the will, then the step-up in cost basis will reduce the taxable gain on the sale - sometimes quite significantly and potentially to zero. If the property is sold by the estate, then it's perfectly possible there will be no tax on the gain - depending on to many factors to cover here.
Please talk with a lawyer on this, before you make any moves here that you may regret later. You need to make "informed" decisions on what's best for your present situation.
