I echo frankiebleyes' thought that there may be something non-scholastic at work, though I would not automatically point to a learning disability, especially if this is a newer development. (She did learn without difficulty before the last few years?)
Without knowing her personally, I would suggest it is more a factor of puberty and environment influences. Have you done a full evaluation of her friends, both those you've met and those that are school only? I ask because her situation sounds very similar to my own at that age, and it needs to be managed carefully but decisively if she's in the same boat. She's well into the development range where influence of peer pressure becomes far more important than parental influence. Without oversharing personal details, I became a) lazy due to normal preteen tendency to test boundaries, but also b) influenced by some friends that were not the ideal group for scholastic (or life) achievement. It started with general laziness in schoolwork, and grew into a daily fight to just get me to go to school. By 14, it was a major problem that nearly meant a repeated grade, along with State intervention due to attendance issues and attitude. My father was given custody and moved me out of the school district and away from those friends, a new Guidance Counselor was heaven-sent and managed to give me a second chance with a flexible transcript policy, and the problem magically disappeared. (Graduated high school in the top 10% of my class, which I promise would not have happened without that intervention.) I might have hated them for it then and a few years after with a passion only a teenager can summon (they were to blame until I woke up and realized what an utter brat I'd been...how they did not drown me, I can't exactly say), but I have nothing but love for them now that I'm able to see where I was headed and what they stopped me from doing.
If she's capable - you are a good judge of that - the problem may be general pre-teen laziness, but please evaluate other influences to be certain she isn't following a peer trend that's disruptive to her full potential. (By the way, my mother never met or knew of those friends until we talked about it years later. They were at school only, except for when we skipped and hung out at our houses when parents were at work.) It could be something else, but if it's a peer influence, it could get worse and out of control quickly.
Not to scare you, but the story struck a chord and I wanted to point out another possible factor.
Without knowing her personally, I would suggest it is more a factor of puberty and environment influences. Have you done a full evaluation of her friends, both those you've met and those that are school only? I ask because her situation sounds very similar to my own at that age, and it needs to be managed carefully but decisively if she's in the same boat. She's well into the development range where influence of peer pressure becomes far more important than parental influence. Without oversharing personal details, I became a) lazy due to normal preteen tendency to test boundaries, but also b) influenced by some friends that were not the ideal group for scholastic (or life) achievement. It started with general laziness in schoolwork, and grew into a daily fight to just get me to go to school. By 14, it was a major problem that nearly meant a repeated grade, along with State intervention due to attendance issues and attitude. My father was given custody and moved me out of the school district and away from those friends, a new Guidance Counselor was heaven-sent and managed to give me a second chance with a flexible transcript policy, and the problem magically disappeared. (Graduated high school in the top 10% of my class, which I promise would not have happened without that intervention.) I might have hated them for it then and a few years after with a passion only a teenager can summon (they were to blame until I woke up and realized what an utter brat I'd been...how they did not drown me, I can't exactly say), but I have nothing but love for them now that I'm able to see where I was headed and what they stopped me from doing.
If she's capable - you are a good judge of that - the problem may be general pre-teen laziness, but please evaluate other influences to be certain she isn't following a peer trend that's disruptive to her full potential. (By the way, my mother never met or knew of those friends until we talked about it years later. They were at school only, except for when we skipped and hung out at our houses when parents were at work.) It could be something else, but if it's a peer influence, it could get worse and out of control quickly.
Not to scare you, but the story struck a chord and I wanted to point out another possible factor.