Can you combine assets from two households, buy a new home together and protect the assets of the elderly parent from the government?

My 85 year old Mom would like to move in with our family instead of assisted living. However, we would have to buy a larger home to accommodate moving her in with us. Is it possible to combine the assets from her house and ours into a new home and also protect her assets in the future? We are concerned that if, 3-5 years from now, we were unable to care for her in our house that Medicaid would come after the assets she put into the new house.