legal question about inspection rights?

OK, Just to add more stress to me, a 70 year old lady, wanting to sell my Mobile Home and the city Lot that I own. My homeless niece and her four children badly needed a place to stay and after the squatters were removed my place was empty. The damage to the kitchen etc my niece agreed in writing to repair things for a cheaper rent. So I charged her only 350 a month. Now I want to sell the place and get rid of the headaches and stress. I sent a certified letter to her so she would know the 24 hours ahead of time for inspection by my Real Estate Man. He was met at the door by the family dog barking and they would NOT allow him to enter the trailer for inspection. Is that legal for her to do that? And yes, I also sent her an eviction paper wrapped in the notice to enter. What should my next step be, ???