How do u limit an iPad 2's connection speed on my network?

I have a 50mb vergin media connection and I pay for it, my parents only pay for 10mb of it and I don't see it fair if my sister is using 50 when she isn't paying so I want to restrict her lpad2 to 10mb download speeds. How would I do this? It would be helpful if I could password protect it too so she can't change back to 50mb.

Thanks in advance.