I'm sorry to hear your daughter's start to the new school year is off to a struggle, but I am glad that you are there to help her.
Language arts encompasses a lot of skills: spelling, grammar, and all kinds of writing. The first thing you need to do is identify your daughter's strengthens and weaknesses. For this you should consult with your daughter's teacher. Ask to set up a meeting with her and you may want to ask that the school's reading coach also be in attendance.
Here are some questions that you can ask during your meeting:
Where do you get the students' spelling words? Hopefully they are using a spelling program that teaches spelling patterns rather than assigning vocabulary words (vocabulary words should not be given as spelling words, especially at this level).
What type of spelling instruction do you provide for the students? Hopefully the teacher doesn't give just the words Monday and then assign a bunch of busy homework like writing each word 10 times and writing definition for the word or use the words in sentences and then a spelling test on Friday.
What exactly do you see are your daughter's strengthens and weakness? How do you know? Ask for specific examples.
What are you currently working on during the writing block? The writing block is usually about 30-45 minutes of writing instruction, conferencing with individuals, time for students to write (and not to a prompt!).
Do you have a schedule of the writing curriculum for the year? This will allow you to better help her at home. For example if they are learning about narratives, you could go to the library and find fantastic picture books that can act as a model. You can read the books together and point out what the author is doing. Or if the class is working on poetry, you can find many poetry books that you can share and read together. The librarian at the public libraries can be very helpful.
Do you explicitly teach grammar? If so, what are you covering now?
How can I help my child at home? What do you suggest?
What is the teacher/school doing to help your daughter?
Once you know the specific areas where your daughter is having trouble, please post another question or feel free to contact me directly. I do have a website that provides educational apps that focus on reading and writing. You may want to check out our free apps (2 dealing with reading and 2 on writing) http://lessonpop.com/shop/join-our-newsletter-get-a-free-app/