Take another look at the original sentence:
You wanted to fix it this way:
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.