Dyslexia

Hello moms, Im having a bit of a struggle. My step daughter is 9 years old and in the 2nd grade. They decided to hold her back another year in kinder. Well turns out she is Double Deficit, which is SUPER dyslexic. She lives with her mom and comes with us on the weekends and I’ve noticed her reading has gotten worse. She tells me her mom doesn’t help her when she’s with her and she gets offended if I say something. So I guess my question is how can I help her learn to read with it? Is there classes she can take? Books for helping kids with dyslexia. If you have experience with it how did you help your child?