Does Power ofAttorney give me the power to prevent certain family members from visiting my husband in hospital?

My husband has been in the hospital for a month with severe pneumonia and lung distress. Before he was put on a ventilator, he gave me Power of Attorney. Had it notarized with the hospital of course. His mother has been coming to the hospital and causing issues. Saying things that shouldn't be said and just creating a very stressful environment. She's never been good to him. Has told him that he is dead to her at least 7 times in his life. He just wants her to love him, but she's never going to. She thrives on drama. My question is this....do I have the ability to prevent her from visiting him in the hospital? He is almost off the ventilator and his stress level is very high right now. She is only making it worse for him.