Mary,
We have always sent the single serve bowls, but if they do ask for packages/boxes, it would be okay to send those.
As far as the mw bowls, we found some in packs of 3 at a Family Dollar store that we have sent, but we also have sent the Rubbermaid containers that have lids in the size that is just over a quart, and enough food for more than one can be prepared at one time as many of them do, or they can use them for storage, so multiple use containers.
Gran