How do you keep a carin terrier away from your pet hamster?

I have a pet carin terrier and my parents say i can't get a hamster even if I pay for it all by myself they say its in her jeans to chase and kill small animals such as a hamster. Im planing on clearing off a high shelf and putting the cage on it where she can't get to it.Even if they don't think its a good idea im probably still going to get a hamster but ... I don't want them to be mad at me so is there a way that I can prove my parents wrong by keeping my (soon to have) hamster for as long as I can?