By making, and keeping up, the payments. Since you accepted responsibility to pay the loan if she did not and failed to do so, you are an obvious credit risk so your score SHOULD go down. The only way to raise your score is to prove (over time) that you are credit worthy and a good credit risk.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
