H.D.
Every flight I have taken let people with small kids board early. Also, no one will stop you if you are among the first to board. I reccommend being aggressive and being at the front of the line. Also most famillies and single passengers will allow famillies to sit together. Especially if you have kids. I wouldn't worry...
But less is more to carry on the plan. I reccomend bringing a stroller and it usually helps you to borad as one of the first. Strollers are also easier with little kids to get to connecting flights. Also try to flag down carts.