J.P.
I think one of the most important lessons we can teach our children is the value of money. I never had those lessons growing up and it has cost me.
I also don't believe a child should be paid for chores or for grades. I once gave my daughter a dollar for doing something above and beyond without complaining. She asked what it was for and I explained. The next thing, she was asking how much to feed the cat and to clear the table. Not the response I was going for! I also did not want to always nag her about helping me out around the house.
I've been giving my daughter an allowance for about a year and she is 6.5 yrs old. It hasn't meant a whole lot to her...but she is saving for an American Girl doll. There are times when we are in a store and she wants something. If I am on the fence, I ask her if she wants it bad enough to spend her money on it and if she does, I will let her buy it with her money if it isn't too expensive.
I give allowance for being a good citizen of the home and school. I felt this was less likely to create an environment of "you owe me because I did something". She is required to put 1/3 into charity, 1/3 into long-term savings and 1/3 into her spending money. She is still young so most of the non-charity has been toward the long term savings.
Her allowance gets docked if I haven't liked her behavior or attitude over the week.
As she gets older, I think it will be important to outline what she is responsible for paying with her allowance or wages from a job. I think that time will come when she is a teenager.
I don't think you should ask family to contribute. I think they should give a gift of their choice. My girl does occasionally receive money as gifts and I let her decide what to do with it. She doesn't have to divide that up for charity.
There are so many ways to spin this that you will have to do what is right for your family. Good luck to all of us so maybe our children won't need the bailouts so many do today!