I did it, and let me tell you how I managed to do it.
CS Clearly mentioned that, it is not recommended to use multiple accounts from one connection, however, you can let them know that you and your sister are providing services on Fiverr from a mutual Internet line.
You also have to tell them clearly, that BOTH ACCOUNTS WILL HAVE DIFFERENT PAYPAL EMAILS (If any), and BOTH ACCOUNTS SHALL NEVER EXCHANGE REVIEWS.
After their consent you can start/continue working safely, Do it today.