This is a total non-issue.

For both TSA and CBP, so long as the names on her ticket appear in some order on her passport, there will not be an issue.

As a likely infrequent flyer, she will likely be required to check in at a counter anyway, but the sole consequence of not having an exact name match will be the need for human intervention to obtain a boarding pass and the possibility that it may take the TSA and CBP Officers respectively each about 10 seconds longer to make the name match.