I really wish that SW would do it this way all the time. I have also seen the entire family line up with Grampa who is in his wheelchair..they all get to board with him. That one flight, I was A16..lucky me...and when I boarded (right behind the medical preboards since there were no business class passengers), the first row, as well as one of the exit rows, were already taken by this family. Grampa sat in the first row with a couple of grandkids, while 4 adults had taken 4 exit row seats. Drove me nuts.
Then, when family boarding comes, you get the same thing...one child that is 3, who gets to board with mom, dad, 2 sisters, a brother, an aunt, uncle and some grandparents!! SW boarding is no place for a Grand Gathering!!! It is supposed to be one adult per child under 4. I would really like it if SW stuck to that ruling...but like Disney, they tend to go with the flow.
This is why I tell people that even if they are planning on doing 'family boarding' they still need to check in at the 24 hr mark. I have heard too many situations where the family figured they were all going to be able to board together, inbetween the A and B groups, but found that the GA allowed just one adult to board with the child, so everyone else had to get to the end of the C line!! And although SW doesn't seem to mind if you save a seat or two, they are going to mind if you board with your 3 y/o and then put jackets/bags on 6 other seats to save them for the rest of your family!!! So, be prepared and checkin at that 24 hr window...just in case the GA adheres to the rules.