"She is my daughter."
Translation:C'est ma fille.
This is a rule you will have to apply VERY often on Duolingo. In French, "c'est" (sing.) and "ce sont" (plural) are used in a large variety of expressions, when a pronoun (it, she, he, they) is subject of verb "être" and followed by a nominal group, ie: article (+ adjective) + noun. - it is + noun => c'est - she is + noun => c'est - he is + noun => c'est - they are + noun => ce sont
Do you know if the preference for "c'est/ce sont" over "il/elle/etc. + etre" is in everyday spoken French as well or is it just a Duolingo technicality?
When I said that it is a rule, it means that this is about proper French, written and spoken. Duo teaches good French and applies the official rules.
They are not absolutely necessary for this section, besides in another discussion you pointed out this; https://www.thoughtco.com/french-expressions-cest-vs-il-est-4083779.
Sitesurf with all due respect your explanation is a bit wrong and misleading to those trying to learn the language. I was turned on to this app bc a friend of mine notified me of this app et je suis francais. :). The "elle. .." form is too acceptable, though the answer given by duolingo is in fact the most grammatically correct. However depending on the purpose of Iearning Francaise, the answer given can or cannot be helpful. if you are learning to write in class this answer is perfect. If you are learning to speak, this will make you sound a bit strange to the common speaker. Still however this is a cute app. :)
elle est ma fille... she is my daughter... c'est ma fille ... it's my daughter.... but i think it will depend on the spoken context...which one would be more appropriate... I am just beginning to learn... so I am not sure whether I am correct...but I do think elle est ma fille is not incorrect...like the computer of Duo states....
but how do you know someone is not saying It's (my daughter -- pointing someone out) -- as opposed to SHE is my daughter
If you are a poet or a bit posh, you can use "elle est ma fille". Otherwise, please remember that when "il est" or "elle est" are followed by a determiner and a noun, you have to use "c'est".
"C'est ma fille" is "That/this is my daughter". "She is my daughter" is "Elle est ma fille". Therefore, the correct answer is, in fact, incorrect. It's two different things.