How to track someone's location on an iPhone?

My parents have a nasty habit of showing up at my dorm unannounced. Now, normally this wouldn't be so bad, but I have a whole day planned out with my boyfriend, who my parents don't know about because they're over-protective and would force me to break up (as they did to my older sister more than once).

So I want to know how I can track my mother's phone, whether through iCloud or her Facebook account (I have her username and password for both, because she shares them with me freely).

I don't have access to her phone because she's in another town, for now. So I can't manipulate any apps on her phone.

Being that your away at college this is the perfect time to step up and act like an adult and set boundaries. Your not a kid anymore, you can tell them in a respectful manner it would be best if you asked me if I have something planned today or let me know when your coming so I will be at the dorm because I'd hate for you to come and I'm off at class or in the library with my phone off studying and I miss your visit. See what I did there.

If you don't own her account then you won't be tracking anybody.

You will probably be a drop out, you can't be this stupid and still continue on in college.

Had you let them know that it *is* so bad for them to show up unannounced you wouldn't have this problem.
You don't need to track them. You need to either tell them about your boyfriend or convince them not to appear unexpectedly.

Findmyiphone or some smart tracker apps like spyphone.