AITAH for giving my daughters one week to leave my house after what they did to their half brother?

I have two daughters. Both over 20. They graduated college and moved back in with me because they couldn’t find a job. The house is my late husband’s house Robert. For context: Their dad and I got divorced 9 years ago. I got remarried to Robert and had my 7 year old son Tom. The girls didn’t have a good relationship with Robert. In fact, they hated him because of what their dad filled their heads about him. They lived with their dad (they chose to) before going off to college.

Robert passed away 6 months ago after a long battle with disease. It was just me and my son Tom. The girls’ dad got remarried last year and the woman is basically a witch. That’s why the girls stopped visiting there. They lived in rental apartment during college and their dad used to pay for rent but stopped after his wife fought with them. The girls couldn’t get a job to pay for rent and asked if they could move in with me and Tom for a while. I, of course, said yes. Although I knew how they felt about Tom. They moved in and they were nice to Tom but also distant.

2 days ago, I had an expected call and needed to leave the house. Tom was in bed all day because he was sick and I asked the girls to look after him for 2 hrs til I got back. I left quickly then an hour later, I got a text from Tom asking me to come home because he threw up again in his room. He said he called for his sisters to help but no one responded. I immediately tried to call them but both lines were busy. I did my best to come home earlier thinking the girls weren’t at home, but turned out they were. One was downstairs the entire time, the other said she was using “kitchen appliances” that’s why she couldn’t hear Tom. I was going to believe them til Tom said he tried to text them but they didn’t respond. I checked their phones after they tried to deny it and he was right. His message was “read” but no response.

I blew up at them both and called them pathetic. They argued that I was making them act like they are the parent and placing resposibility on them. I knew this wasn’t about that. They hated Robert. Fine. That might be a little understandable. but Tom is a kid and he has no part in all of this to be treated like that. I knew they neglected him on purpose. So I told them they have one week to move out and they started arguing and even crying saying I’m being too harsh on them, and acting worse then their dad’s new wife. I said this wasn’t up for discussion and now both of them are giving me the silent treatment. Basically making me feel guilty about the whole thing.

Maybe I’ve made a wrong decision. but seeing how they’ve neglected their brother merely out of resentment and hate makes me feel upset and quite concerned to have them around him.