Dear Katherine,
You're the mother. You have very strong, powerful, and legitimate instincts. You are correct to follow them, and protect your child, especially in the instance of her very necessary medical care. If the doctors and other care-givers are not stepping up and fulfilling every part of what it takes to care for your daughter, then it makes total sense that you can just feel it.
And I think you're right, just because things are going better (which of course, of course, is the best, most wonderful and amazing news!!), doesn't mean you don't have to keep giving the most excellent, and vigilant care. Be on the lookout for things, keep your eyes, still, wide open. I mean, hello, they're doctors. They're not "on a break", just because of remission. They shouldn't have to be reminded of that. But, maybe they do.
With doctors, trust is key. With my primary care doctor, I trust her so much, I kept going to see her even after I moved a ways away from the town she practices in!! Do you have someone in the office that you trust the most? Can you find a moment where you can ask to talk? Then just find a way to break in to a talk about it, hopefully in a fairly non-confrontational way, like you said, "not in anger", and make your concerns known, and see how things go?
I wish you, and your whole family, most especially that precious little girl, all the very best. I know that talking to those doctors can be nerve-wracking. (they're just people just like us, too, though...and they're there to work for you, to take care of your precious baby girl. Let them know what you need. It's OK.)