What's wrong with "she doesn't have daughters"?
Genitive plural (daughters) of дочь is дочере́й
The robot voice says something like дочи, I can´t hear the /r/ ...
Yeah, I'm wondering if the р is just supposed to be silent in this word...(?)
"she has no daughters" excuse me where's the difference ??
«Дочери» is singular here. If you wanted to say "daughters" you would use «дочерей». «Дочь» is an irregular noun, so it isn't as straightforward as many other nouns.
Why is is it дочери instead of дочеры? This seems to violate a spelling rule about и and ы after certain letters.
The seven letter spelling rule simply says that и must be used after К, Г, Х, Ж, Ш, Щ, Ч. This does not imply that all other letters must be followed by ы.
...Then WHO'S FLYING THE PLANE??
Why no есть here? There never seems to be any pattern.
It's because it is a negation. I think of the нет as a combination of не есть if thats helpful.