Another explanation is that your daughter is slowly but surely making the difficult adjustment from a self-contained special program to the environment of the regular class. The regular class might simply be more challenging than the SLD program. The fact that your daughter's grades have improved a bit is a good sign. I hope this trend continues. You should be aware that having a learning disability should not impair your daughter's chances to get into a good college.
Many colleges have excellent programs for students with learning disabilities.
Descriptions in a college guide book will include this information, or your daughter's college counselor can help you. My son, who is extremely bright, has Tourette's syndrome, ADHD, ODD, OCD, and learning problems. He's had voluntary modifications, but they're not working anymore. He reacts violently at school to his classmates' taunting and does not want to go back. The medications aren't working and his doctor wants to hospitalize him.