[Essam ABDOU]

I think the correct answer is

Her father paid her fees; otherwise she wouldn`t be here

It`s a case of Mixed Conditionals. Originally the sentence is:

Her father paid her fees therefore/that`s why she`s here (NOW)

or

She`s here (NOW) because her father paid her fees

- "couldn`t" cannot be used here because the meaning refers more to conditional cases than ability or possibility. We normally use would/could/might in the main clause of 2nd conditional sentences; however, when the clause is in the negative, wedo not use COULD because it would refer to lack of ability.

It`s like: The US team won in the injury/stoppage time; otherwise they wouldn`t be in the Round of 16

Best Regards