Open houses legal while tenant still lives there?

[Nyla Smith]

My husband and I have just bought our first rental property. We've decided to get rid of the basement tenant for various reasons, i.e. the previous owner said she was consistently late with rent, she's hostile to work with and extremely high maintenance. 

We spoke to her and let her know that we wanted to have an open house while she's still living there. We initially asked for two dates, but she refused. She verbally agreed for one date. We have a date for tomorrow, Friday, the 15th, from 6-7. We've had more than 40 interested people. She just now sent me a text, saying she refuses to let anyone in, that she's checked with Utah state law and it's an invasion of her privacy to hold an open house while she lives there and that she'll contact police and an attorney if we go through with the open house.

Does anyone know anything about this matter? We're trying to be as accommodating as possible with her, but I don't appreciate the legal threats. Thanks for your help.