Legal Question in Family Law in Maryland

It's unclear from your question whether you are the owner of the property or a leasehold tenant. You use the phrase "my house" which suggests ownership, but you also mention "the lease", which suggests there is a lease and you are the sole signatory as a tenant. There is a court procedure known as a wrongful detainer action, which you would file in the Maryland District Court in your county. You can get the complaint form, which is CV-089, at the nearest District courthouse. You will note on the form that you can seek damages and legal fees in addition to possession of the property. It is a fairly quick procedure, although you will have to have her served with the court papers in order to be entitled to damages. And even when a court orders her out, if she refuses to comply you'd have to hire an eviction company to remove her belongings (unless it's just personal items) and schedule the eviction with the sheriff, who is there to maintain order. On the other hand, if you are the owner and especially if you are also occupying the premises, I see no reason why you can't change the locks while she is off premises. You would then have to arrange for her to peacefully retrieve her personal belongings. If you're concerned about her reaction and response, you might contact law enforcement to see if someone can be present to maintain peace and order upon her expected arrival.