In my research, I ran across a reference to a daughter of Red Cloud who had a daughter named Susan (aka Nancy) Rouleau/Sears/Clark. Susan Rouleau was born at Ft. Laramie on 12-6-1856. Her mother died shortly after and was buried at Ft. Laramie. Susan's father was Hubert Rouleau (1796 to 1887) a Canadian fur trapper and trader. Hubert was 1/4 Sac & Fox. Susan's mother White (Buffalo) Calf/Cow was Oglala Lakota, from the Bad Face band. In Susan's bible it states that "her mother was White Buffalo. White Buffalo's father was chief Red Cloud". Susan had two brothers Jesse James Rouleau and John Rouleau. The reference also contains family stories and there is a sad account by Susan (aka Nancy) Clark (she married Sears, was divorced and married Clark) of the aftermath of the Wounded Knee Massacre when her presence (she was a midwife) was requested at the Episcopal church at Pine Ridge where 33 severely wounded Lakotas, most of them women and children were brought. All of this information was connected to a family tree on ancestry.com with Hubert Rouleau and Susan Nancy Rouleau. Hubert Rouleau later married Eagle Woman and Minehie Shell Woman. Has anyone identified information connected to other wives and children of Red Cloud (aside from Mary Good Road and their children?)
This is also my family tree and I came across the same assertion that I was possibly related to Mahpiya Luta. What I found was writings referring to Red Cloud as grandpa, but not as father. Any old leader in Lakota culture could be referred to as grandpa especially within a tiyospaye or hunka family. Sister wives were a thing, but I don’t think in the context that we see with Mormon polygamist. I have not seen the census rolls for my family, but I’m afraid it wouldn’t show much past White Buffalo anyways. What I can tell you without digging into my research again is that White Buffalo Cow Woman (not to be confused with the name White Buffalo Calf Woman) was the daughter of a man named Flint River and a woman named Leg High. I have not seen those two names on any rolls yet, but a second cousin of mine found them somewhere and I’ve not had the time to investigate it. Additionally I’ve done the math on the ages of Red Cloud, Hubert Rouleau, and White Buffalo Cow Woman and the numbers don’t make sense. Indeed he probably was grandpa, but biologically I’m not sold. Hubert and Red Cloud were close friends and I’d bet the marriage of Hubert and White Buffalo had something to do with Red Cloud. I’m also thinking since they were Ite Sica that maybe Flint River passed on and Leg High became a sister wife to Red Cloud however that is just my speculation.