There are numerous tales of exactly this woe on FT. There are some carriers which absolutely require the card used to make the purchase. There are other carriers which have procedures in place to permit substitution. Generally speaking these requirements are enforced by carriers and in locations where CC fraud is rampant.

Because the carrier bears the responsibility for the fraudulent use of a CC, it's fair for the carrier to protect itself.

Regretably, what this means is that if you make a purchase for a future service with a card which is later replaced for any reason, you absolutely must contact the carrier immediately and determine whether and what arrangements can be made.

Some will allow you to appear at a ticket office with various forms of ID, some may not care and some will care.

OP's sister's best hope here is that she can coax a refund for the unused ticket out of the carrier.