Yes, it's my understanding that you can change the BB reservation to be different room guests or to different dates, as long as the lead person on the room, probably you or your husband's name) doesn't change. If you want to change your dates afterwards, the new dates have to be part of what is offered in the original BB offer.
So, for example, if you want to make a BB reservation for 1 room, under your name, with your husband and DD as guests, for a time when they are offering the
Free Dining, you can change your dates to another time that is also part of the Free Dining BB offer, and change the other guest names (but not yours as lead), or even add an additional person to the reservation, as long as the room accommodates the total number you now have. If this isn't correct, or I've misstated something, I'm sure someone else will chime in, but you could also ask when you book your BB if you still have the question.
Let us know what the current offer is, and what the dates are for that offer. I'm hoping for a RO discount for early March.