In the novel, Jane Eyre must make many difficult choices, [including forcing] herself to leave the house of Mr. Rochester, the married man she loves.
Why is [for example, by forcing] wrong!!!
because it’s a run-on.
“For example” is most often used:
- at the beginning of a thought
ex. The book has quite a few plot holes. For example, it’s never explained why the main character came to town.
- at the end of a thought ex. The book has quite a few plot holes. It's never explained why the main character came to town, for example.
- when set off by commas in the middle of a thought ex. The book has quite a few plot holes. It's never explained, for example, why the main character came to town.
Notice that #3 DOES NOT MEAN between thoughts, as in your sentence. “In the novel, Jane Eyre must make many difficult choices” is one complete thought (comparable to “The book has quite a few plot holes” in my example). It cannot be connected by a comma to another thought; that makes it a run-on sentence.
Answer: because “forcing” is the appositive of “choices.” Both are nouns. Forcing is a gerund noun.
You need parallel construction. “Including” signals the gerund which “equals” one of the choices she must make. One of those choices is not “by forcing.”