No exemptions can be made. We are not even suppose offer to accept cash and then charge our own card, nor are we suppose to solicit this option from other Cafe patrons. If someone offers, then it's fine.
The only exception I personally make to this policy is unaccompanied minors, who's parents ignored the notifications on the website, in the station, and (for those that escort their kids to the train/Cafe car) all over the Cafe. Though I'm not working a long distance trains, so it's easier for me to hold this stance.
This is always my thought, when I encounter someone who claims they didn't know about the policy.
Just out of curiosity, when is she heading out on the train? Cash has returned to certain local trains, and is suppose to be back nationwide in about 2 weeks or so.