Sounds right to me. After Britney Spears had 4 albums she went with a Greatest Hits for example, and I think three is a good choice, since she really has had a lot singles to go with.
"Genie In A Bottle," "What A Girl Wants," I Turn To You," "Come On Over" (All I Want Is You)," "Dirrty," "Beautiful," "Fighter," "Can't Hold Us Down," "The Voice Within," "Ain't No Other Man," "Hurt," & "Candyman."
That's 12 singles there and I think "Reflection," "Car Wash," and "Oh Mother" will probably be added as well to make 15 songs plus 2 or 3 bonus tracks with one being a single. Sounds like a good idea to me. ;p