Being ambitious for your family and creating a positive impact is a good thing. It reflects that you believe in the power of giving and in making the world a better place.
Being greedy reflects that you care only about your ego, thus the more you have, the less it appears to you.
There is a fine line between ambitious and greedy. Some people go to extremes to become powerful and famous at the expense of their family and their balance.
Be ambitious as your family and the world needs you to be that. However, be on guard for not getting into the greedy territory in the guise of ambition.