Yes, she will be silver elite after the outbound, and can enjoy all the benefits on the return trip.

Her boarding passes will have the "Elite Access" logo printed on it, either when doing OLCI or at a kiosk at the airport. She can use the elite line (i.e. blue carpet) immediately.

If she wants a temporary card, log on to continental.com. On the multi-colored "My Account" page, there's a link in small prints under the Elite-o-meter that says "Print Duplicate OnePass Card". Click there and print her own silver elite card.