Final answer:
The question about Jackson's sister lacks context, making it difficult to answer accurately without additional information or clarification, especially if 'ITB Crenshaw' is relevant to the question.
Step-by-step explanation:
Without context, it is challenging to provide an accurate answer to the question, "Who is Jackson's sister?" This question seems related to a specific storyline or real-life scenario that needs additional information. However, if this question pertains to a known historical figure, literary character, or person of note, one would need to research that individual's family or biography for a precise answer. In the case that 'ITB Crenshaw' is a clue or a typo related to the question, clarification would be necessary to proceed with a factual response.