Answer:
Insert a semicolon before in fact
Step-by-step explanation:
"She never found the shipwreck in fact, she had no interest in diving."
In the above sentence, there are two independent clauses but are related. Normally, the best way to grammatically rewrite the sentence will be to use a comma right after 'shipwreck'. But, as that is out of the option, the revised sentence will be best rewritten by putting a semicolon before 'in fact'. Also, the semi colon can also be used to introduce a new sentence that is still related to the previous sentence.
So, the new sentence will become
She never found the shipwreck; in fact, she had no interest in diving.