Why would my sister put our Mother's maiden name as her middle name on Mother's checks?

She uses these checks to pay Mom's bills. I understand giving your mother's maiden name as an identifier, but I don't understand why it would appear as my sister's middle name on the front of the checks. The address is my Mother's address and my Mother's name does not appear at all on the checks.

A few months ago I reported my two sisters to the State for spending a lot of our Mother's money on themselves, without Mother's knowledge. I am in the process of trying to obtain more financial information from them that they refuse to give me. I do have some information. But I want full disclosure. I am curious if putting her name on the checks is legitimate.

Does anyone else do it this way?

My Mother has been completely manipulated and "groomed" over a period of time to "stand by" my sisters. I have basically been "thrown out" of the family now, even though I am the sibling who has always been there for everyone, including my parents. In trying to be there for my Mother, I have "upset the apple cart" for my sisters. I trusted my sisters and went on "good faith" with them. I obviously was wrong to do things this way. I am devastated and heartbroken.

Caregivers….. Please….. Make sure you do everything legally and in writing. Do not leave anything to trust and good faith. Be completely transparent in your dealing with parents' finances. Big mistake not too.