Won't Stop Getting iMessage Notifications?

So I have an iPhone 6S and my mom has a MacBook Pro for her work. She doesn't really use the Mac much so I use it a lot more than her. At one point I had connected my iMessage to her MacBook. She needed the computer for work one day and I logged my iCloud out. I went through and deleted all the conversations still left on there. I had the Mac off for a few days and when I turned it back on all my iMessage from my phone for the past few days were blowing up on there. Even though I was logged out. And had deleted all the messages, they were back. I don't know what to do. I don't want all of my messages being on there in case my mom needs her computer. That's just weird. And they won't go away! Could someone please help me figure this out?

Factory reset an iPhone 5 without previous owner's password?

I'm not techy at all, so please keep it simple. My aunt's sister gave me an iPhone, but it has all of her a information on it. I really want to reset it and put my stuff on it, but I don't have her password. I asked her, but she doesn't remember it and it's too much of a hassle to keep bothering her over it. How can I reset it without her Apple ID password? I can't even sign out without it.

How to turn of Voice control? I have an iPhone 6s?

OMF VOICE CONTROL KEEPS POPPING UP EVERY FREAKING 3 seconds and I already turned off Siri (it was doing the same thing so I turned it off so now voice control is annoying me) it's so annoying and unneccecary.