That's rough Ben. I had a semi-close friend who had stage 4 cancer. The last time I'd heard from her she'd gone into remission and was taking internet remedies along with a second treatment of chemo. We don't know what helped but personally I'm not sure I trust the government with cancer issues. It works for many, and in the US it probably costs insane amounts. Not to mention the side effects. I recently learned that my friend had passed away in the summer. She's had a rough life but always held strong to her faith. I've learnt that faith helps to no end, especially in the darkest of days. Although I wouldn't pray very often, she'd remind me how important faith is. She was a practicing Muslim and believed that God was the only one she felt she truly had, and now she's with Him.
A pert of me still hasn't fully accepted it and blame myself for not keeping in touch. I probably couldn't have changed anything but I did a heck of a lot of reading and had seriously considered footing the bill for a Rick Simpson treatment using THC. She'd was already in her second round of chemo and I didn't want there to be a third. It's nothing anybody should have to go to and while some people claim that any other remedies are snake oil, I'd try anything I could if it meant helping a friend.
I hope it's just temporary and that your daughter gets better soon. I definitely think you should consider treatments away from the US as mentioned above, and even try other alternatives if possible. I'll donate something soon. If you don't mind I'll try to share this on facebook too.
All the best