You get credit for your railfare and the accommodation charge, she gets credit for her railfare (assuming that your name is listed first on the reservation).
Both passengers get the points for their own rail fare (if they're AGR members). The person listed 1st on the reservation gets credit for the accommodation charge - if that person is an AGR member. If not, it's lost - and nobody gets the credit! (Even if the other person is an AGR member!)
When you get the tickets it will have the total dollar amount on the stub. You get the points based off this amount. The first person on the reservation carries the value of the sleeper and that value is printed on the that persons ticket. If you want the points you need to make sure your name is first and when you get the tickets make sure the accommodations charge is on your ticket.