How long does a female cat remain in heat, and how often does it happen?

My daughter Mất tích her house in a foreclosure, and wasn't allowed to keep her cat (Snickers), so I've smuggled Snickers into the flat I rent.
The cat is about 2 years old, has already had 4 litters, and she's definitely in heat.
Living in a big city, I'm trying to make sure she doesn't get outside hoặc get pregnant.
She's been making all kinds of noise, and I've been trying to give her attention to quiet her. I'm not supposed to have any pets either, so I'm trying to prevent her from being discovered as well. For about the past week, I haven't got much sleep, as I've been having to get up with her like a baby.
I'm just curious as to how long I have to remain sleep deprived, and also, is there any way to speed things up (without Tomcat attention)?