Yeah it is too busy for an official portrait according to the rules. But you don't have the makings of a portrait anyway. No clothing theme, not a great location, mass posing takes the rules out of play.
Here is the way I look at this: "look at all the memories on that wall." I would just take pictures of what is on that wall for posterity. This picture will be looked and enjoyed for not only who was in it and their relationships, but look at the location and the value of the things on that wall.
Lighten the overall exposure, correct the distortion by the wide angle lens, correct the overall blue cast, slightly darken the edges and you have a winner for this family and yourself.
Save the rules for when you are really working your craft.
