Excellent, considering that to get anything from A1 through A15 you have to buy Business Select tickets.
You will be among the first in the A group to board. The only people who will board ahead of your group will be disabled and special needs passengers.
When you get on the plane, you will be able to choose any seats that are not already occupied (except exit row because your child cannot sit there). If no one buys the business select seating (the most I have ever seen in this group is five), excluding any disabled preboarders, you will be the ninth and tenth people to board. The only thing that may be a concern is that if the plane is coming from another destination and there are people already onboard who are continuing on. If there are a lot of them, you'd likely still get seating together, but closer to the back of the plane as continuing passengers are allowed to move and many of them may move up front (but this will be a concern only if there are a lot of continuing passengers).