I must say I think this is the first time I've heard of a member bringing a "book report" to each meeting but it's definitely not the first time I've heard of a group having trouble with a member who consistently takes over the meeting and seems oblivious to other people's views on the matter!
If you encounter a person who insists on taking center stage at each meeting and it's annoying a majority of other members, you might simple want to tell her straight that this is not acceptable! Sometimes telling it as it is, as gently as possible, is less hurtful to feelings in the long run.
If you don't feel able to do this, then how about finding a way to 'redirect' her. For example, perhaps you as a group could thank her for all her work but say that it would be even more useful if she could summarize the book and the discussion after the meeting rather than during it. In short, you'd be making her the meeting secretary, responsible for recording the key points of the book and the conversation.
Then, most importantly, encourage her to email her notes to the members before the next meeting so there is no need to discuss it at the meeting - but make a point of thanking her for her work.
Personally, I would be tempted to take the direct approach but, as you're not comfortable with that, perhaps the option above will redirect her energies and having a record of each book and the key points discussed might actually be interesting to look back on over time!
Anyone got any other ideas?