I have a general judgement order but wasnt given any information

Good morning
This appears to be a pre-action disclosure application for information.
Your sister has asked the court to order that you disclose your personal bank statements and invoices presumably because she is contemplating litigation against you.
The court has power under the Civil Procedure Rules to order you to discloses this information so long as the requisite steps have been met.
First your sister or her solicitor should have written to you setting out the basis of any claim she has and request disclosure of the information she seeks.
Secondly if you fail to comply with that initial request she can make an application to the court which you could oppose. She would have to demonstrate that you will be a party to the proceedings and disclosure of the material will help to identify the issues and settle matters sooner.
If you did not receive the initial application and the matter was heard in your absence you can appeal the order on the grounds that it is wrong in law or fact. But you cannot appeal on the basis that court does not have power to order disclosure of personal information - it does have such power.
Ignoring the order could amount to contempt of court which carries sanctions such as a fine and/or imprisonment.
Alex