can I legally throw someone out of my house and change the locks after giving them a 30 day notice?

I have someone I let move into my home temporarily until she could find a place to stay, It has now been 4 1/2 months and she has been a total nightmare, acting crazy, disrespecting me and my home and tried to destroy my marriage. She has also gotten violent with me on several occasions.I have asked her to leave several times and she tells me she is never leaving. I gave her a 30 day notice and she laughed in my face and threw it on the table. The notice was up a month ago and she is still here. She is ruining my life. I spoke to several Attorneys and have received conflicting information. I have been told by some that legally since her stuff is here and she is getting mail here that the only way I can legally get her out is to file an eviction and that legally I cannot change the locks and put her stuff out. She also has her two kids living here. Another Attorney told me that I can now give her a 3 day notice and the change the locks. I am so confused. Can anyone please advise??? I am desperate