"Everyone has another mother" worked, but it calls into question what this sentence is really trying to say. Perhaps its a German ambiguity? Or would my translation not actually make sense?
debatable, but I think "a different" is much more similar in meaning to "eine andere" in this context. Saying "one other" in English implies that the person has two mothers and sounds strange and imprecise.
but is this not a valid literal translation - such as are accepted elsewhere here on duolingo. and to be honest, without any context the former sounds more or less strange..... (something to be thought about by those writing the sentences and deciding the system of approval. a difficulty that is probably almost inevitable given the aspirations of the site, but which is by no means a major shortcoming.)
I think you have to consider the sentence when you're reading it and wonder about the meaning; "eine andere" would usually translate to "another".
"jeder" (also: "jedermann") refers to "everyone" which can be both women and men which is why it is always masculine. "jede" is feminine and only refers to women.