I will assume that you were probably insolvent when you paid the money back becasue of the size of the debt over 10 months.
Did you borrow the money from a creditor to pay your sister back?
If this is the case then the OR will identify the loan repayment and class this as a preferential payment ( i.e. you preferred your sister over barclaycard etc ).
The OR then has the legal power to overturn the repayment and take the money back from your sister.
it also sounds like you have a lot going on with charging orders etc so although you have had some advice you may want to speak to someone to get ideas of timings etc.