Take a look at the original sentence again:
Carla has difficulties getting to her 8 a.m. English class on
time, she always watches too many late night
movies and then hits the snooze button on her alarm once too often.
You wanted to fix it this way:
Carla has difficulties getting to her 8 a.m. English class on
time she always watches too many late night
movies and then hits the snooze button on her alarm once too often.
To delete the comma between time and she would cause an equally bad problem, a fused sentence. A fused sentence occurs when you have two main clauses joined with no punctuation whatsoever. Carla has difficulties getting to her 8 a.m. English class on time is the first main clause. She always watches too many late night movies ... begins the second main clause. The spot between time and she needs a stronger break than blank space.
You might want to consult the rules for fixing comma splices and fused sentences.
Go back to the sentence to try again.