Family Member Loan

There has been a lot of discussion in the personal finance blogosphere about this topic. Some people think it is the right thing to do and others think it can only cause problems. The reason I bring this up is that I received a call this morning from my sister and she asked if I could loan her $2,500. It is but it isn't a lot of money so I really couldn't decide what to do. Needless to say, the wife and I had a long discussion ranging from expectations of payback, can we afford to even help out, should we charge interest. We finally reached a consensus that we would help out this one time. I am going to try and keep my expectations of payback low and if they don't come through with repayment I will chalk it up to experience and make every effort to let it go so it doesn't become a source of contention within the family.