"You are my child and I am your father."
Translation:אתה ילדי ואני אביךָ.
The best translation of (feminine) child is "ילדה", since בת is closer to "daughter" or "girl". But in this case, since it's "my child" and it's her father talking, I think "בת" should be accepted (את בתי ואני אביך).
Should probably be accepted (but bear in mind - like in my previous comment here - that הבן שלי means "my son" so it's not an accurate translation)
No matter what I did, it said my answer was wrong even though it matched what it said it should be. After many attempts, hoping it would accept typos, etc., I tried downloading a third party keyboard with nikkud for my iPad, and then when I had the vowel it accepted it. So Duolingo’s requiring vowels now suddenly? For just this one question, or will I find more?