있어요 is a word that is already conjugated. It is not an ending. It comes from 있다 - to exist, to have. The ending in 있어요 is 어요. 어요 goes hand in hand with 아요 and 여요. Which one you use for a colloquial present tense depends on the vowels in the stem (here, 있).
있다 is also not an ending, it's just a word. It means "to exist, to have".
이에요 again is not an ending, it is a conjugated word. It is not an ending. It comes from 이다 - to be. It has a unique conjugation in less formal uses.
You can't try and attach these on and form questions.
The correct answer is "저 여자가 예뻐요?".
예뻐요 is not an ending either. It is just a conjugated word meaning "pretty". It comes from 예쁘다.