I'm having trouble understanding why you believe you have a contract with your aunt? Just because a family member agrees to support you throughout college doesn't mean you have a cognizable cause of action against her? If she was deriving a tangible benefit from you and your sister going to school, then, perhaps, you could argue their is consideration, but you simply have not provided enough information to establish a contract. So, are you saying that the only reason you went to college was because your aunt promised to pay for it? I think not. As for your sister, you have no cause of action as to money she might have lent your aunt. Whether or not she can sue her is another question all together. Good luck.
Stewart is correct in his analysis regarding consideration. There may be more to the story, of course, so maybe you could show that your aunt was expecting to receive some benefit from the arrangement, as opposed to simply promising to give you a gift.
Even if you could, however, you still have a problem with the statute of frauds. Presumably, the amount of money you were expecting from your aunt is greater than $500, right? Agreements of this sort have to be in writing.
I agree with my colleagues. From the facts given it sounds like you do not have a contract with your Aunt. Speak with the school and let them know about your financial situation. Many schools will work with students so that they do not have to withdraw. Do they have any work study programs? You may also want to try reaching out to other relatives/friends to see if they might be able to assist you financially. I wish you the best.
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