"Ought I to be very much pleased with 'Marmion'? As yet I am not. James reads it aloud in the evening" - I always enjoy the references to the books JA has been reading (or in this case, listening to) and her remarks on them. Here, it seems that she is asking Cassandra, in a very tongue-in-cheek and typically wry way, whether Sir Walter Scott's Marmion (published 1808) is a poem which was 'in fashion' and about which everybody was talking.