Hello,
Caution: You may not be able to use your own (your sisters) consultancy's services if you decide to go for a recruiter profile in most of the organizations as it may be considered unethical / conflict of interest.
For the question you had asked: Yes, you should mention about the work you have done. No matter if it is for your own consultancy. If you have done it you deserve to mention it in your profile.
Regards,
Caution: You may not be able to use your own (your sisters) consultancy's services if you decide to go for a recruiter profile in most of the organizations as it may be considered unethical / conflict of interest.
For the question you had asked: Yes, you should mention about the work you have done. No matter if it is for your own consultancy. If you have done it you deserve to mention it in your profile.
Regards,