According to tos, provided each person is an ACTUAL person and does things independently of each other, you will not have issue.
My wife and I both do swagbucks. We both do apps/surveys/etc. We both live at the same location, with the same IP.
A few things you'll want to consider:
Both your sister and yourself need to have separate devices. DO NOT RUN YOUR APPS ON HER DEVICE. If you only have one device/one computer/etc, do not even attempt signing up your sister. Get a second (third, fourth, etc) device, THEN sign up. (You can find cheap devices at c7recycle.com [I am not affiliated with this, but I've used them before and they have fast, free shipping, and nice devices at times.] This also means no checking your swagbucks account from her computer or vice versa. Computers use cookies. Most other devices also use cookies. Cookies will be the death of your (and her) account if cookie 1 says you signed into swagbucks and cookie 2 says she did afterward.
Have a copy of both your and your sister's government issued identifications ready to send in to swagbucks when/if requested. This is the only way swagbucks accepts legitimate users from same IP. Addresses need to be exact.
If your sister will be making any decent amount of swagbucks, DO NOT refer her. It's better in the long run for the both of you. Swagbucks has the ability to shut down anyone's account when it chooses. They have a higher tendency to close accounts down when they aren't making enough off the account. (or if they're having to pay out of pocket to have an account stay open [too many referrals]).
Cash out often. This is true even if you didn't sign your sister up on same IP, but doubly true for you. You don't want to have involuntarily stumbled into something that will have your account closed because both your sister and you have done an offer that only allows for one per IP. It happens, and a single oops moment will have you dreading keeping that extra $5+ in your account if the ban hammer comes down.
A closed down account doesn't mean a perma-banned account. They close your account, reopen a new one. You'll have to start over fresh, but if you're just doing this for a few pennies a day or such, it's no big deal, really. (Again, cash out often)
Hope this helps.