I am a single father and cannot work. Are there any grants or scholarships my 10 year old daughter may qualify for martial arts study?

Start with the dojo (or several area dojos) she might join. One of them may have a grant or scholarship program for low-income or special needs or talented students. Also, go to your local public library's reference department and ask this question. They will have a list of area businesses, churches, foundations, etc. that award money for situations like this. (For instance, I live near the Ty Beanie Baby and McDonald's corporate headquarters, and we all know they award money for various community and personal needs.) The reference librarian may have other avenues for you to explore.

Do some research and let me know how it goes.

Agreed, ask the school, We have one here in Atlanta GA that is a Christian Martial Arts school,
The most a student can pay is 40 dollars a month. And if the parent or guardian meet the guidelines set up by one of the various non profits that help with scholarships It can be free or at the most only 5 dollars a month.

They have to prove they are on government assistance

So there are many schools like this, most don't advertise it highly,

Some schools may allow the student or the parent to work around the DOJO, answer phones, clean up, paint and more. They also may get them to help with advertising