Unless, of course, the library gave her the wrong spellings of the names.
I tend to agree with you..
While the artist could be held somewhat responsible, it was the Library's responsibility to review the art and sign an agreement that the art meets their requirements..
As a commercial artist, I am familiar with the need to "proof" all work for proper grammar and spelling..
But a Fine artist does not generally work with text...
I am used to making notes of all "questionable" spellings, use of grammar, etc.. and providing all suggested changes to the contractor for approval..
Usually, the contractor will also "proof" my work, and note any changes, spelling errors, etc...
It is then their responsibility to "approve with noted changes", or require me to "make noted changes and re-submit for approval".. so they can proof the art again..
Only when all changes have been approved by the customer do I have "final art" to be sent to production..
So, in defence of the artist, I would suggest, unless they can show final, approved art with correct spellings, it was the Library's responsibility and not hers..
If they simply let her "do her own thing", then they have no one to blame but themselves..