It is such a common problem that there are several suggestions in the
Wiki FAQ.
The recent
Consolidated post-transition orphaned credits thread should also be of interest.
Worst case scenario you could spend $50 to buy 2,000 points. After using 254 to top off the Award your wife would have 1,746 points remaining, worth $29.10 toward WGA fares. So the net cost of topping off the Award would be $20.90.