pulled pork
crockpot beans with hamburger
coleslaw
watermelon
small buns
pickles, sweet and dill
cornbread muffins
brownies and rice crispy bars.
i want keg rootbeer

If you have a facebook invite posted and Mom has sent 50 invites, I assume those are mostly for families and couples, not single, you better plan for at least 150. So I am estimating for 150.

pulled pork- 45 pounds ready to serve, this is about 65 pounds bone in raw plus sauce
small buns- each pound ready to serve makes 5 regular buns or 10-12 slider buns
pickles, sweet and dill, 1 gallon each
add onions, about 12 pounds thin sliced
add 3-4 quarts table sauce

crock pot beans with hamburger, she needs 3 gallons (4 #10 cans or 8-10 pounds dry beans) per 100. Basically 2 electric roasters full for this party. Make at least 1 large crock pot meatless for any non-pork eaters attending, label it. Be aware that 2 roasters will blow most household circuits, if you use an extension cord to reach a second circuit, it needs to be heavy duty, and taped down

coleslaw- 3 gallons, about 25-30 pounds, per 100

watermelon, 1/2 bound per person, and allow for ice and recruit ice chests, or pack in ice in a bathtub to chill

cornbread muffins, about 150. Sheet cornbread would be easier and just as , 2 full sheets, which is 8-10 9x13 pans.

brownies and rice crispy bars- cut these small and then allow 2 each per person