How we do our event is we have a steering committee. which consists of the chair for the auction, donation chair, advertising chair, decoration chair, basket chair and fundraising chair. Each chair has there own committee underneath them. Depending on how many volunteers you have and what interests them. the steering committee meets once per week to track the progress of their committees and reports back to the chair.
the coordinators chairs (like) donations chairs would then have a meeting with just her donation volunteers and then would assign them a department. IE... restaurants, spa and beauty, large corporation, home and gardens. whatever your categories are for your silent auction. Each category would have a team of four to six people.
The chair should not do anything with donations. the chair has too many other things to do. the steering committee meets to update the chair.
She should have a donation coordinator to do this. Make a list of all categories for your auction assign 4 to 6 people in each category. have someone that just does phones. one person that just picks up donations. one person that just is on email and two that go and hit the pavement.
we usually get between 6 and 7 hundred items. it is amazing how much you can get when you are organized.... and your chair is willing to delegate....
hope this helps