What are my rights concerning a shared property with my sister?

Did your mother leave the property to you and your sister as joint tenants (own the property jointly and survivor takes all) or tenants in common (each owns undivided half interest in property)?  If you own it as a tenant in common, you can sue for partition of the real property, meaning that the interests will be divided.  If it is impractical to physically divide the property (as it seems to be from your description), the Court may order the property sold and the proceeds divided.  I am not sure if this can be done where property is owned as joint tenants, but maybe.  At any rate, the Court may order your sister to allow you to use the property equally with her. In addition, if your sister has been using the house and not letting you do so, she may owe you one half of the use and occupancy value of the property for the period she has excluded you (in other words, your sister has to pay rent for her use of the property; since she owns half, she only has to pay you for your half.)