Answer:
True.
Explanation:
As per the context given in the question, she(sister) would best use this experiment of 'putting the tomatoes in sun and shade to compare the results' to persuade me as this experiment attempts to support her claim logically that establishes the credibility of her claim and compels me as an audience to accept and believe her claim. She employs the 'experimental' research method to show the consequences of manipulation of an independent variable('sun') on the dependent variable 'tomatoes' to observe its impact(ripening) and reach a valid and authentic conclusion. Therefore, my sister would persuade me even though she's not a scientist as this experiment substantiates her claim reasonably. Thus, the given assertion is true.