How can a life tenant be rid of the obligation to pay property taxes and insurance on said property-- My Mom has life rights to a house but is now in a nursing home?

It depends on the terms of the life tennancy...if she was to pay the tax and maintain the property as long as she exercised the tennancy...then she pretty much has to....if she doesn't wan the tennancy anymore, she can give it up to the remainderman, (who presumably then gets all ownership and rights to use) and he would be responsible.