"Neha's sleeping on the floor" is accepted, but only with a warning that I 'missed a space' (and.. uh, swapped an 'i' for an apostrophe). It should just be accepted.
I reported it, but not on mobile so there's no box to explain the issue - just commenting here to explain why I reported.
Whoever's person's house this lesson is about, has no walls, a very cheap and old door, a cheap and old car, has 2 windows and a very cheap roof. The person's brother sleeps on the the floor, Neha sleeps on the floor and sometimes the other people too. What a typical poor house!
"Neha sleeps on the floor" is in the simple present tense and implies that she habitually sleeps on the floor. It would be translated into Hindi as 'नेहा ज़मीन पर सोती है'.
The given sentence 'नेहा ज़मीन पर सो रही है' is in the present continuous tense and is telling you that the action is currently in progress. So, it would be translated as 'Neha is sleeping on the floor'. When you see the helper verb 'रहना' in a sentence, it implies that the sentence is in the present continuous tense.