Munchkin is very lucky to have you.  What you do for Munchkin her own mother does not. Hope that doesn't bite you in the ass one day. These daughters can turn on a dime.

I think you have hit the nail on the head, neither PARENT wants to do anything to help Munchkin...your DH is very lucky to have you, not many women on this site would be willing to raise a man's child for him while he sits there twiddling his thumbs.

Couple of things:

1.) Your DH doesn't get to give up. Tough sh*t if he thinks she is being lazy. He needs to get off his arse and deal with her and STOP LETTING HER BE LAZY.

2.) You all gave her too many outs and choices. Until her assignments are caught up, she doesn't get a choice. She sits down and does English. Then she does art. Then she records for orchestra whether she likes it or not. The ability to do things how she WANTS comes in AFTER she does what she needs.

3.) TT's house isn't an option. Don't give her a choice. She stays with you all until it's DONE. TT can call the cops and file contempt if she wants, then she can explain to a judge why SD had to stay with you all.

4.) Did I mention your DH doesn't have a choice? He's no better than TT, and I wholeheartedly mean that.

You need to put pressure on your H, Clove. If he isn't willing to engage, then you are wasting both time and energy.

Get tough with HIM.

I dont know what the outcome to all this will be and dont have any suggestions.

But, I'm betting Munchkin will file your spreadsheet in the back of her brain.  Someday, way down the line, she will be up against a time-sensitive task and wondering how to get it all done.  I bet she will pull out that memory and think, " Oh, yeah, I remember when Clove did such and such".  A lot of time, as parents, the most important thing is our example, never what we say, but how we conduct our lives. 

So please don't feel that your time and effort are wasted.  Hoping for the best possible outcome.

CLove, I have a lot of admiration you.

For your H? I have a Double Flying Five Fist Monkey Nut Punch. Big old poopie head. *diablo*

So, I just had a meeting with the leadership team of the clinic I work at - and all of us are saying that all the patients we work with are having trouble with remote learning. The teachers are too. The kids are really struggling with how to stay organized and get everything done when their parents aren't home and no one is supervising. They don't learn well remotely. It's harder to get extra help. It increases social anxiety to be asking questions via video. 

I don't think she's lazy, I think she's a kid who is struggling during a pandemic. She may also have some mental health issues (all kids with a mother like TT do) and that's exacerbating it.  That being said, it won't work if you are the only adult trying to help her.

I've read through responses... and your responses.  Just a few observations/suggestions.

1.  Like Tog said.. this situation is tough on a lot of people.. I am not so certain your skid has a laziness character flaw.   She is for sure procrastinating.. and it sounds like she may have taken some courses that are not totally in her wheel house too.. but it seems that she is having trouble getting to the point of organizing her work and getting it done.. primarily when she is at her mother's  house. I mean.. we all can have a bit of lack of motivation from time to time.. but I think her issues transcend just being a "lazy child".

2.  Dropping classes shouldn't be an option for her.  The art/orchestra... both should be doable for her.. Art is an "easy" class.. and she needs to finish what she started in Orchestra.. and perhaps not pick THAT again in the future?  Don't allow her to just put off her work.. procrastinate till it's too late and then give her the easy out now.  Make her follow through and then she can learn how to make better choices for her courses in the future.

3.  TT's house can't be an option for her with her schoolwork.. not if anyone expects her to succeed.  I am not saying she can't go there.. just that she can't go there and have anyone expect she will complete her work.. so visits at mom's need to be only allowed in amounts that don't interfere with her completing her work.

4.  I'm not saying it is your obligation to help her.. but it's clear her father and mother are either uninterested or incapable.  The school can only do so much to spoon feed her the work.  If you want to help her.. that is a choice.. but it is not your job and you can let her deal with it how she will.. but alternately...throwing money at an issue and then throwing your hands up when she doesn't immediately follow the schedule won't work either.. she is going to need a lot of hand holding .. and that hand holding needs to be at your home.. it isn't going to work long distance from mom's.

5.  So.. sending her to TT's with freshly purchased supplies.. throwing money away.  What needs to happen is that she needs to be in the home where she is being helped.. that is yours.. and she needs to be there to show her progress on her plan.  So.. that may mean just a couple days at mom's vs a week.  Clearly, she has proved she can't handle the lack of oversight.  Only when she is right there in front of you can you really pin  her down to get her to complete  her work.  And.. you certainly can provide her with "private" times to do her orchestra work to finish out those assignments.. Hey we are going to pick up dinner.. do your orchestra assignment when we are gone..etc..

I don't think she is hopeless.. but she is not mature enough to make the right choices for herself.. and still doesn't understand how to keep herself on track.. she needs hands on assistance.. and in person.. not just checking after a day or two.