Menu Ideas...

My Son is Gluten free.

The parties I did for them this summer was Hamburger , hot dogs and beans. With a huge bowl of grapes and strawberries (they were in season).

Hidden gluten- anyting with flour, most canned soups.

We have also done the simple chillie or sloppy joes, but also pulled pork (cook in crok pot with apple juice, shreed and put out a few different BBQ out for people to use) ..
Alls of these thing, what makes is gluten free easily to give with out bread ( my son does this all the time).

Good luck

How about bagels with cream cheese and lox as an option? You can pick up some G/F Udi's bagels, also offer some strawberry preserve (tasty with cream cheese), and maybe offer some peanut butter for kids as well. You could also offer turkey slices too, for those who find lox too rich or are unfamiliar with it. Cold cuts is another route to go. You can offer apple slices and carrot sticks (both go well with peanut butter) and deviled eggs if you have the time/inclination to make them.

10AM party. I am being serious when I ask, will anyone show at that time. I know I ever would have. Make French toast, bacon for kids. All kids love French toast. Or PB n J sandwiches. Gluten free should bring his own food. Coffee n bagels if any adults choose to stay. Cake.

mini pizza bagels
pigs in blankets
chicken fingers or nuggets
fruit kabobs

I'm sure at least one of those can be gluten free, but you don't have to have the whole menu gluten free for one child. Speak to the child's mom and make sure but I think I'd do that stuff. Make it all ahead of time, just warm it up and voila.

This is one of my favorite brunch things:
http://allrecipes.com/recipe/green-chili-casserole-2/

If the kiddo with the dairy allergy can have eggs, you can make a small dish without the cheese and use soy milk. I did fruit kabobs for my kids recently and they were a big hit!

I would make and/or buy a variety of items for brunch:
-scones
-bagels (you can get mini ones for kids)
-sausage
-hashbrowns
-scrambled eggs
-small cereal boxes
-danish
-small patter w/sliced turkey, salami, sliced cheese & small bread slices
-coffee, orange juice & apple juice boxes for the kids