EmilyM

I actually teach for a virtual charter. I've never heard of a virtual school sending an in-person 1:1, but that only means as much as my experience. 
The biggest hurdle I see here is your question about learning coach vs aide. Because of the nature of the school, your kid has to have a learning coach provided by your household. We can complain all day if that's fair or not, but at the end of that day it is a charter you chose to enroll in and a public charter likely isn't set up to send out teachers to individual households willy-nilly. In my experience, most often a parent does this role, or a close relative. I've seen families hire out for it, but it's extremely unlikely you'll get the school to provide you a learning coach.
I'm sure you get this because you ask about it. I just wanted to be clear about this.
So to argue for a 1:1, you're going to have to show where your reasonable duties as a learning coach end and where your child's disability would begin. Learning coaches tend to do more or less what a 1:1 would do, so you'll need to show where the extra help is needed.
I like @Lisa Lightner 's suggestion of possibly hiring out for this, but you'll still need to be careful you're hiring for a 1:1 and not a replacement learning coach if you plan on arguing for a school-funded 1:1. Be sure you truly don't fall into the trap of using that theoretical person as a babysitter or to handle the main job of helping with schoolwork.
I can't stress enough how carefully you'll need to keep these things separate.
The way I envision this is you'll help with the meat of the lessons, but the 1:1 would be the one keeping your daughter on task, perhaps implementing the breaks and schedule.
My school has had its share of kids struggling to pay attention. Most suggestions and accommodations given are various forms of breaks, alternative schedules, and movement time. My prediction is this is what would be suggested first, do be prepared.
And if you do get that in-home 1:1, yeah, they'll likely try to hire near you. Which could be helpful if you know someone.