is this sentence correct.....

To complete her Week 3 Discussion, Sharon isolated herself from her family, which finally made them realize she needed to concentrate.

Yes.

Try:

After Sharon isolated herself from her family in order to complete her Week 3 Discussion, they realized she needed to concentrate.

Training for the up coming ten-mile marathon,Lizette includes more protein and complex carbohydrates in her diet.

Yes, the sentence you provided is grammatically correct.

To determine if a sentence is correct, you should consider a few factors. Firstly, ensure that the sentence has a clear subject and verb agreement. In this case, the subject is "Sharon" and the verb is "isolated." Next, check that the sentence maintains proper tense consistency. In this case, the sentence is written in the past tense.

To confirm if the sentence is correct, you can follow these steps:

1. Identify the subject and verb: In this sentence, the subject is "Sharon" and the verb is "isolated."

2. Check for subject-verb agreement: The subject "Sharon" is singular, and the verb "isolated" matches with it correctly.

3. Determine tense consistency: The sentence is written in the past tense, and the verb "isolated" agrees with it.

By following these steps, you can ensure the correctness of a sentence.