Hi,
It is not a matter of if Wellesley can give you an affordable offer, but will Wellesley be an affordable/financially feasible opton for all four years you are there. Remember you myst apply for financial aid every year. Your family owns their own business which is going to be different from a salaraly job because the ebb and flow of income will be different to predict.
You cannot have your dream school be a financial nightmare for your family.
Update - I visited Wellesley yesterday and was able to talk to my financial aid counselor. They said that their system was assuming much more investments due to the dividends my parents gained from the business. My counselor was able to fix it and a new aid offer was just sent out today. The new offer is much more affordable for me and my family, so from my parents and I, thank you for all your advice and for helping me through the process.