Debbie, there is precious little about me that is definitive, I admit. However, I happen to be a great great grandson of W.F. Schrafft a/k/a William Frederick Schrafft, the Boston confectioner. William Frederick Schrafft is said here to have been the brother of a Charles Frederick Schrafft who was born in Stuttgart, Germany and emigrated to New Zealand in, I guess, the 1840s. The W.F. Schrafft family had no connection to Stuttgart. The point I was trying to make is that the family knows that W.F. in fact had a brother named Adam and a sister named Sophia, all three of whom emigrated from Bad Wildbad in the Schwarzwald to the United States after the death of their father. There are also public sources for W.F.'s connection to Adam and Sophia. On the other hand there is no known sibling named Charles Frederick Schrafft, said to have been born a year or two after the death of the father, and no known family connection to New Zealand, and I don't believe there are any public sources for the assertion here that Charles Frederick and William Frederick were brothers..
I only meant to mention in passing that there might have been one or two additional siblings of W.F. who died in infancy. FamilySearch trees, and in some cases public sources cited in those trees, refer to, among others, a Carl Friederich Schraft (circa 1824-1825) and another Carl Friederich Schraft (circa 1831-1831) as brothers of W.F. See, e.g., https://www.familysearch.org/tree/person/details/GZGD-62R. I don't necessarily buy into the notion that W.F. had half a dozen additional siblings, but there is a certain logic in assuming that there might have been siblings born or baptized in Bad Wildbad before the death of the father who spelled their last name with one "f" -- the preferred family spelling -- and who died shortly after birth. Families were big in nineteenth century Europe, and death was common.
I don't encourage you to add any siblings of W.F. Schrafft to your tree. I only encourage you to delete any family connection of W.F. Schrafft to the Charles Frederick Schrafft described here.
Thanks, and best wishes.