Hi,
Has your daughter always struggled in math? It's common for kids to have their strengths and weaknesses. I, for one, am not a math person, but I did really well in english. Have you tried talking to your daughter's teacher? If your child is just beginning to have trouble this year, maybe she just needs a little extra help. It could be the teacher's technique, it could be the type of math.... I had a great teacher for algebra, and I did very well in that class, considering math is not my strong area. When it came to geometry, however, that was a whole different story. You should look into a private tutor that can work one-on-one w/ your daughter. If that doesn't help, maybe have her tested to see if there's more of a problem. Also, speak to your daughter and get her feedback. Maybe something's going on in the class, or maybe your daughter doesn't want to do the work b/c it's hard for her. These are all things you have to rule out. Also, since your daughter is doing great in all her other subjects, can't the school just hold her back in math, instead of having her repeat 6th grade again? This way she'll still be w/ her friends and able to move on in all the other areas she's doing well in.