Hi,
In some cases, it will be made clear that the legal owner is not the beneficial owner.
The legal and beneficial ownership of property may be separated by a valid declaration of trust.
Please see the following:
Declare beneficial interests in joint property and income for completion and conditions of a Form 17 application.
This will be relevant to yourself and your wife.
Your sister will declare her income from property separately and cannot be included in any Form 17 application.
Thank you.