If you are arriving at the same time, there is no reason to not just put the reservation under your name with her name as the secondary guest. You can let her pay for it and have them change the invoice to her name, if necessary, at check-out.

Otherwise, you're just asking for unnecessary hassles. Even if she has a corporate rate, that could still be made in your name as the primary guest since she will be with you and can clear up any issues with qualifying for the rate.