As the assignment was to create a mini lesson for reader's workshop here is my idea:
The teacher will begin the designated reader's workshop time by telling students that today they will be reading the BEST story ever. The teacher will have the story pre-selected. The story should be a non-fiction informational text. The teacher will either read the story to the students themselves, students will read alone, or the teacher can project a digital copy of the story in the front of the room accompanied by a voice recording.
After the story is done being read or listened to the teacher will again tell them how great this story was and how it was the best thing they have ever read. The teacher will look to the students and ask for their approval that "don't you agree with me, this story is awesome." If all is going well within the minilesson there will be at least some oposition from the students. They will probably begin naming titles of stories or books that they find to be better off the top of their heads.
To respond to this critique by the students the teacher will ask how anyone can say anything other than this story is by far the best of the best. A student will tell the teacher that they disagree and why they disagree. When this happens, the teacher will use it as a segway to the next part of the assignment. The teacher should ask students that when he/she told them this was the best story every was this a fact or was it an opinion?
Students will then catch on to the lesson that fact and opinion are not the same, and one person's certainly does not make it a fact. The students will see the connection between the two and understand the difference. This will then lead itself into a class discussion about what is a fact and what is an opinion. This discussion can probably be best recorded by the teacher keeping an anchor chart going while students define the terms and respond to one another's answers.
After the class discussion of fact versus opinion is over, students will be given a book to read independently. They will also be given a pre-designed anchor chart displaying which parts of the facts and which are opinions. If the students were paying attention to the direct lesson/instruction from before than they should have no problem corrrectly completing the assignment.
Content differentiation for two students can be as follows:
Students who may struggle reading the book can be provided with a partner to read aloud to them or a CD version of the book on recording. The student can then hear the content of the story which is essential in helping them to differentiate between fact and opinion.
Another way the content can be diferrentiated for a student is a pre-created notes guide. If a student struggles with whole-group instruction or is unable to follow along in large anchor charts as a part of class discussion, they can be provided with guided notes; an outline of the material with blanks that they will fill in as the teacher and discussion moves along.