DLJ
What I think Mommy/Wendy (her real name) is getting at is this :
Getting married is a serious decision that will affect you for the rest of your life. It involves great responsibility, sacrifices, and how you behave as a married person will affect others in your life as well. If you believe marriage is for life, choosing a marriage partner is probably one of the greatest decisions you will ever make in your life. It will be more important than what job you have, where you live, or how much money you make.
Getting baptised covers much the same responsibilities. Once you are baptised, you are treated more seriously. Greater responsibility is expected of you. If you are not baptised but commit a sin, you are not shunned or criticised the same way, are you? You are also expected to be able to make decisions and accept responsibility for those decisions you make, based on how you interpret what the Society says about issues. I don't think I need to go into all the ins and outs of the expectations and responsibilities that go with being a baptised Witness for you DLJ as you have been raised as a JW just as I was.
Now, would we expect a child of 12 to fully appreciate the responsibilities and expectations of a married person?
If the answer is no, then why believe a child of 12 to fully appreciate the responsibilities and expectations of a baptised person?
And I am not saying baptism is a bad thing.
But it is not fair nor morally feasible to "encourage" a child to baptism any more than we would expect s/he to chose a life-long marriage partner at that stage in life too.