"My child was born."
it should definitely be accepted, regardless of what we've "been taught" . . . they're already assuming that we know so much, it would be hard to separate "known" versus "unknown" information, and expect us all to answer exactly as they want us to, every time.
Kodomo ga umareta = perfect Japanese
Because が is a subject marker and は is a topic marker. In this example, the verb "to be born" is directly related to the subject "my child."
If it had been 子供は生まれた, it would mean "regarding the topic of a child, it has been born," or for a more natural tranlation "children were born"
So the は denotes regarding the topic of child/children being born.
が means this specific child that we are discussing was born.
This sounds good, but honestly doesn't sound sufficiently convincing me: "Regarding my child, he/she was born" sounds like perfectly fine form.
Furthermore, I believe to have seen similar sentences using は instead of が.
My take is that が is being used instead of は just because the topic is something else in the given context. For example: - (Hey what's new about you?) - (About me/the news,) my child was born.
Literally 先生 is “first born” (as in born earlier, not “first-born child”). That later became a form of address for older people, then in general of males whose education was demanding of respect (particularly teachers and physicians). In Japan the meaning later narrowed to just “teacher”, but regardless of gender (I’m not sure if it can still be used for non-teachers in Japan; in Korea you can use the equivalent word to address for example doctors as well). In Mandarin Chinese on the other hand, it has two different meanings: 1. basically like English “Mister”, 2. a colloquial word for “husband”.
I’m not a native speaker but my guess is that 生まれる probably works in a similar way to verbs like 始める. Meaning that the progressive is used to mean that the subject continues to be in the state that results from the action: 映画は初めている "the movie is in the state 'begun' => has begun, has started", 子供が生まれている "the child is in the state 'born' => was born, has been born".
“my” is implied by default, unless you are talking about a different person.
For example, if you’re in a conversation with coworker X and they say: “I wonder where coworker Y is, I haven’t seen her in a few days.” Then you could answer: 子どもが生まれました ”[Her] child was born”. But if you suddenly twittered the same sentence (so there is no context to speak of), then people would understand it as implying that it’s your child.
Of course you could add わたしの if you really wanted to be clear, but you normally wouldn’t unless you fear that the other person might misunderstand if you don’t add it.