We need to save for my sister\'s college

My big daughter Sarah is going to college this Fall. I did not have much money for her college for I worked these years in academics and earn as little as an postdoc, $40,000 a year. I need to save money for my daughter's college.
One day, I took Amy to a shopping mall. I saw Heelys was on sale. It was about half the original price. I wanted to buy one pair for Amy because she had told me many times that she wanted to have a pair of Heelys shoes. She is a very energetic girl and like the things a boy likes.
She tried the Heelys shoes and found one that fit her. When I want to check the Heelys shoes out, she changed her mind. She told me that she would not want the Heelys shoes. I asked her the reason. She told me that we need to save money for her sister's college. I was shocked because she is only six year's old.
Now, Sarah have got admitted by MIT. We are all happy. I really need to save money for her college expense.