So I'm trying to do the Heartache by Number quest and I just finished the part of a different quest where I talk Cass into selling her Caravan. I then talked to Alice McLafferty and ended the quest. After that, Heartache by Number updated and said I should talk to Cass about something and she mentioned how she wanted the Van Graffs dead (Which I had already killed) and Alice McLafferty. I don't want to take the negative Karma hit so I was gonna bring Cass along and let her do it but for some reason it won't let me take her as a companion even though I dismissed Ed-e. There are also no other options besides the "Take her along" orders and my quest says "Find Alice McLafferty at the Crimson Caravan Camp and 'Settle Accounts." So what should I do? If I kill her and take the Karma hit will the NCR become non hostile again? Or is my quest hopelessly bugged ? By the way I looked in the safe next to her desk and theres no incriminating evidence...

Do you have another other human companions with you?

Just Boone. Can I only have 1 human companion or something...?

yea you can only have one human and one non human

Yes you can only have 1 human companion following you.

Ahh... I assumed since it worked with Boone and Ed-e I could have two.. But regardless it still doesn't solve the quest errors and if she will kill McLafferty herself.