Just to clarify, it isn’t by when you booked your seat, but what category of fare you bought & when you purchased the EBCI. Someone could have booked their WGA ticket on release day, but not purchased EBCI until a week before their flight. They’d always be behind everyone with BS, Anytime, A list, WGA+. But they’ll also be checked in behind anyone with a WGA ticket that bought EBCI before they did. So to your question, if you have WGA tickets, you will be behind all those other fare categories & anyone else with a WGA fare who purchased EBCI before you.
How close is your trip? If it’s just days away, you may be only a few slots in front of people without EBCI. Is that worth it to you? Some people think it’s not worth it & just take their chance at checking themselves in. Another option may be to upgrade your husband & 9 yo’s boarding position at the 24 hour mark. NOTE: this option MAY or MAY NOT be available. If there are any spots open in BS, A 1-15, they’re offered as upgraded boarding. From my city it costs $45. The option is bookable online at the 24 hour mark, right as you check in if it is available. It is a gamble if it will be available of course, but it’s another option.