She wants the following items:
Penne ala vodka
Stuffed shells
eggplants parm
sesame chicken
sausage and peppers
sauteed green beans
green salad

I assume you are doing the light foil trays, so half pans are safer, because the larger ones tend to fold when filled with heavy foods. Carry them on cookie pans, NOT by the sides. A half pan holds just under a gallon.

Penne ala vodka- 8 pounds dry pasta, 1 quart sauce per pound
Stuffed shells- one shell per person, amount varies on size of shells

eggplants parm- 4 half pans

sesame chicken- 1 pound raw boneless per 3 persons
sausage and peppers- 1 pound sausage per 5, equal amount veggies

sauteed green beans- 24 pounds fresh

green salad- see the plan for 100 tables

I suggest you need an appetizer table, and here is why:

Before the Buffet; Why You May Need an Appetizer Table
A self-catered buffet is a real challenge to the organizers, and things don't always come together as smoothly as hoped. By planning and setting up an appetizer area or "nibble table" which is ready when the guests begin to arrive, the cooks and servers have time to complete the arrangement of the dinner buffet. This is especially critical if there are children among the guests, or there is a wait before dinner, as at a wedding reception.

This does not have to be complicated. Three items, plus a punch, or two if one punch is alcoholic, are sufficient. Typically, include a fruit tray, a cheese tray and an attractive dip or spread; or you can go with a dinner theme such as TexMex with chips, salsas, Texas caviar and guacamole; maybe shrimps if budget permits (Do allow 1 pound per 5 people).