If you and your sister each own half the house, as tenants in common, then her half goes according to her will. If none, and it was her separate property, then it goes one-third to her husband and two-thirds to her issue (or if she only has one child, half-and-half). If your mom is living or you hold as joint tenants, it would be different.
Answered on Nov 12th, 2013 at 5:25 PM