There is no way to store contacts on the memory card.
If she's on a BES, that means her device is syncing with her mail client (i.e., Outlook). Unless there is some corporate policy that requires her to have all those contacts on her device, she could go into her mail client/account and delete the ones she won't ever use (and she can use the 'Lookup' function to find people if she needs them later).
Once she deletes them from her account, the deletion *should* sync to her device (unless the BES Admin turned that off, which would be, IMO, stupid).
No longer a BES Admin, but it was fun while it lasted!