I allowed my ex to continue staying in my trailer. There was never any rental agreement & the lot rent is in my name. She doesn't pay me any rent, she only pays the lot rent to the management company. When she doesn't pay on time, it reflects poorly on me. She has been living there for approx. 2 years & this has occurred more than once. What are my rights? Do standard landlord-tenant laws apply when there is no rental agreement & rent is free? Please help, I want her to vacate so I can sell & be done with this hassell.

Yes, she is your tenant and you have to go through a formal eviction process.