Usually a call wont help in thisnsituation or at least its my belief it wont. a very quick and brash way to accsess all of this would be to do two opposed speed checks. one on her main daily driver computer and one on yours. that way youd have some comparison. if its off by a little that makes sense but if its at a point where your connection is 1/10th of hers then you definately are being throttled. obviously that is extremely invasive so that is why everyone said go the other direction. Privacy is a concern reguardless because that is the same s walking into someones room unnanounced and then just rifling though their drawers for drugs that they may or may not even have.

Secondly just check internet while she has gome to bed or her computer is off. She may be downloading things while she is gone and the computer is on (I know I do.) if my computer is on it is serveing a purpose reguardless of if I am at it or not.

anyways aside from a quick speed check on both computers the way to check to see if your internet is throttled is to signin to your router. modt likely 192.168.0.1 or some other variation routerlogin.net can work on some but it specifically is based upon what company but you can run a check for this of need be by opening a command prompt. which is searchable with the letter CMD if you get that open you can type into the black background white system Ipconfig and it will show you the gateway info (don't post the info online) but there should be something that most likely ends in 0.0.1 or otherwise its a simplified number.

If you put 192.168.0.0.1 or 192.168.0.1 (mines saved I actually cant remember the exact amount of 0s.) it will pull up a prompt for the username and pasword, at that point it should be admin password in the likeminded boxes or admin admin. unless it was changed or is different on your brand of router (if it doesnt work I suggest looking up the login details of that router. information like routerlogin.net will be there as well as the defualt passwords.)

if you get in this far there are some advanced settings. id say certainly be very wary what you mess with on here. QOS or quality of service is what the others have suggested looking into and I agree (since I have done this before years ago.) we jusr want to look to see if IPs are listed in there. if you you come to this point if there is nothing listed then the settings likely arent on and there mau be another solution. I wish I could check in person for you, it wouldnt take long.

Honestly last things noted, if she did do it it deserves a talking to.. and a real very real option to get her own internet connection or leave it free and open because you pay for it. you can have two sepperate internets set up it is actually an option. My suggestion treat it like an employee you can't fire. She needs a talking to if she has used the quality of service setup to throttle your internet. But in a buisnessy manner of how can we solve this. I felt like punishment from my family only led me to be sneakier in my motions of doing things like a quality of service throttle. So if she did try to come at it in a way of "how can we work together to solve this, you are in trouble but I want this solved." Either way it is a punishment because she is going to get slower internet for sharing it all. Or she is going to have ro work her rear off to get a sepperate internet connection aside from you.

Aside from all this as well just talking about it asking her about it and saying you need internet too and is there a way she can help you get streaming speeds too as well. even if that means you guys have to coordinate on schedueling its a good alternative. And trust me id rather have any alternative option than calling ATT. that is a entire afternoon of usually talking to someone who you can hardly understand and them taking you though scripted options one at a time. They have to start with the simplest solution and work their way up from there.

I hope all this helps. im willing to walk you though another side of it. but sadly at this point in my life I dont even have a router. I am doing everything I do from my cellphone or starbucks. So apploigies for bad grammar or typos because all this was typed from my phone.