Are my husband and I too old for this?

I'm 2 years in to my bachelors degree in psychology-I'm 21 and he is an architecture major -24. We have decided that we're going to go to med-school together. Mainly because we want to help as many people as possible and even try doing doctors without borders. Anyway our families have told us we're "senseless" and it doesn't make sense to be a doctor and not do it for the money and we'll finish in our 30's. I know it takes money to live a "rich" life, but we've realized that at the end of the day it would make us feel fulfilled. I'm going to do pediatrics and he's going for general practitioner. Anyway are we told old and has anyone else decided to do a career change so drastic? I don't care how long it takes especially when it will allow me to help children who don't have insurance or are too poor to get the proper attention they need.