How should I react when my 15 year old daughter gets bad grades?

[Snow White]

She's a big girl.
Encourage her to do well and help her when she asks. Punish her if she fails. But, she will just have to suffer the consequences if she fails.

[Angela F]

At 15 she's old enough to be responsible for her own grades. I would schedule parent teacher conferences to see if the teachers can suggest what the problem is. I personally will ground my son, he's 14, from the phone or whatever he likes to do until he pulls his grades up. This usually works pretty well with him. You can't feel bad about this, her grades at this point are her responsibility.

[Laura B]

TAKE HER TO GET TESTED AT A SYLVAN LEARNING CENTER. IT'S EXPENSIVE BUT YOU FIND OUT WHAT HER LEARNING ISSUES ARE AND WHAT CAN BE DONE TO HELP HER. YOU MIGHT ALSO WANT TO GET HER THERAPY TO HELP HER WITH ANGER MANAGEMENT. SHE MAY EVEN HAVE A LEARNING DISABILITY.