Hi Lorraine,
Do you have any documentation that you lent the $10,000 to your partner? As well as documentation that you have been demanding this money back?
You have two options, you could either:
(i) sue your partner for the return of the loan; or
(ii) enter into a financial agreement with your partner given your separation and as part of the agreement, ask for the loan.
Suing for the loan requires evidence of you having made the loan and that your intention was for the money to be a loan and not a gift.
At family law, after a long partnership, de facto partners, like divorcees, may enter into financial agreements for division of assets and property they shared in during the period of partnership. If partners cannot agree, the court may step in and determine what is a fair and reasonable division. There are many principles the court (and yourselves can) use to assist them in determining what is a fair and reasonable division of assets and property after a relationship. Take a look at the LawAnswers thread
"separation - how much is fair to split with my ex" for a breakdown of these principles. In the assessment, any loans or gifts or contributions provided by you into the relationship, your shares assets or property, or directly to your partner will be accounted for as part of your contributions into the relationship.