K.S.
Martial arts are great, but you and your boyfriend -- how long have you been together? She has a "very part-time dad," how long has that been going on? You just lost your job, which means there's been a change in finances. Your kid is probably feeling the strain.
Being an instructor qualified to run a karate school probably takes a good decade. First degree black belts can't run karate schools. It's a good hobby for you and it's great you're volunteering and that you have an outlet. This is a great outlet for the family and kudos to you for it.
But writing the chores down on a white board might help you out. They may help you see whether you're demanding too much of her. Is she expected to get dinner, for instance? That's too much. Also, if she has to clean her room, she needs you to teach her how. Is there too much clutter in her room? Help her sort through toys she doesn't play with any more.
Martial arts and homework, picking up her room, help putting the dishes away, putting her own laundry away, that's reasonable. But make sure you aren't asking too much of her.
Just because she could handle something before you lost your job doesn't mean she can handle it now. Sometimes a lot of big changes in a kid's life cause them to act like a child a little younger.
Good luck!