Thank you for responding and wishing for me to further assist you. It's appreciated.
Please note that I'm not an attorney, thus I cannot specifically give you the points you so seek for this is something that you must discuss with another attorney, perhaps yours? I can tell you though that in such a case, one can file a MOTION TO EXCUSE ________(name of party - in your case, your sister in-law) DUE TO CONFLICT OF INTEREST.
The only thing that can be done with your sister in-law is for her to be excused from the case for which the Motion is the legal process and will so do if approved/ordered by the judge.
I do understand your concern, and I do feel that it is inappropriate for your sister in-law to be your wife's legal counsel in this particular case - simply, this is prejudicial.
An attorney can go into greater detail with you concerning such conflict of interest and if you so wish, prepare the Motion to Excuse.
I hope this has helped.
Peace, Love & Happiness,
The Mystic Wave
Information provided herein is based on my 30 years experience as a legal secretary/paralegal in the State of California, with experience and knowledge in the State of Nevada. This information is not intended to substitute for informed professional legal advice from a practicing, licensed attorney.