What if some of the games or crafts were things like Kaya would have done- she always struck me as a "non-girly" girl. You could even "stretch it a little" and send them on a "treasure hunt" in the back yard where they are following the clues to track down the prize like Kaya would have used clues in the woods to find her way home.

You could try to enlist the 10 year old nephew as a helper in an activity- if you think it's going to be too "girly" - just do it in a way to make him feel special, not excluded- e.g. You know, this make your own tiara craft is really complicated, do you think you could help me out by running the glue gun- I just don't think the younger kids can do it. That puts him in the position to still be involved in the activity, and he can work on his own if he wants, or he can assume the role of "helper" if he feels he's too manly to do the activity.

Or what if, like from the Samantha movie with Eddie's money jar- your nephew is Eddie. You give him a baby jar with change in it and send him into the back yard while the others are doing something he wouldn't enjoy to hide it. Then see if the others can find it. Tell him to hide it really well- he could give "warmer-colder" clues as they search. Then the kids split the money. I once did a treasure hunt in our sandbox when my daughter had an under the sea party and hid change- less than $1 worth in mostly pennies, nickles, a few dimes and one quarter-the kids acted like they were looking for real buried treasure and got so excited when they found a coin- I can't imagine the jubilation if they found a whole baby jar that they could share- just make sure the money divides evenly.

Sorry this is so, long- I'm just rambling about some ideas that are popping into my head. Have a great party!

Jo