It's time for an important lesson.
1. Never lend a cousin $10,000 AND
2. If you were the cousin lucky enough to score $10,000, never post on social media bragging about buying a Burberry coat.
The situation sucks for her, but is a juicy family drama for us.
Two years ago my cousin's dog was diagnosed with a life threatening medical condition. The veterinary bill eclipsed $10,000 AUD. My cousin didn't have the necessary funds, and for whatever reason ended up in my house begging and pleading for a loan.
I should mention here that I'm not rich by any means. Rather, it's the fact that I'm the only person in our family that (1) has a steady job and (2) has no major expenses. My partner and I lived frugally for a long time to save up an emergency fund. The loan came out of these funds.
The loan agreement is simple: $10,000 over a maximum duration of five years, paid monthly, and accruing interest rate pegged to my mortgage offset account's interest rate. There is no 'formal' contract per se (though one most likely exists at common law). But there is an understanding that she will pay the loan back as soon as possible.