Looks like it doesn't matter if she already has a Dividend Miles number. Only if she is or is not a current subscriber to the e-mail updates.

>>** Bonus Miles Terms and Conditions: Dividend Miles member can earn 500 bonus miles per qualified E-Savers subscriber. Limit of five qualified E-Savers referrals per Dividend Miles member. E-Savers subscriber referral must not already appear on the US Airways E-Savers subscriber list to qualify for the mileage bonus. Dividend Miles member must refer up to five qualified E-Savers subscribers by October 31, 2000, to be eligible for the bonus. Only the original e-mail recipient qualifies for the bonus miles offer. Only one Dividend Miles member will be eligible for the mileage bonus per E-Savers subscriber referral. Please allow three weeks for bonus miles to appear in your Dividend Miles account. All official Dividend Miles program terms and conditions apply.<<