Remove additional icloud mail accounts

Currently, when I go into settings, scroll down until I see iCloud, my Apple ID is listed. If I press it to go into the iCloud settings, then my Apple ID is listed up top and under it is Family, which has their new Apple IDs. Are you saying to delete my Apple ID from the device?

• On that same page, all the way at the bottom where Advanced Mail settings is listed, they have a default account they send from, and below, where it says "Allow Sending From," 3 additional @icloud.com addresses are listed, and none of the accounts listed is the one I just setup. From what I can tell, they might have tried setting up their own Apple IDs because they were tired of receiving each other's text messages, so in the settings listed under Advanced, and then Mail in the iCloud settings, I want to wipe all of these IDs from their devices completely and just have my Apple ID linking to the App Store (I assume that's how it's done using Family Sharing) and then have their new Apple IDs, Would the best way for me to get rid of all these accounts is to reset all the settings or if I delete my Apple ID from the device, as you suggested, would that get rid of all of them?
• Also, I have all the data backed up locally so losing something from icloud wouldn't be a big deal.

Yes, I'm trying to setup Family Sharing because in the past, their devices all had my Apple ID, so they could buy apps and music, but as they're getting older, they're tired of sharing the same Apple ID, mine, because when someone texts them, they both get it.

I've already setup Family Sharing using my Apple ID, and I assume I've set it up correctly, so when you first enter the iCloud settings, my Apple ID is at the top of the page and under it lists their names, which is where it used to read Family Sharing. Now that they each have their own iCloud account, I'm trying to setup the device to use it, but from what I can tell, it looks like they tried setting up their own Apple accounts because they were tired of receiving each other's texts. When I go to advanced iCloud mail settings (at the bottom of the iCloud settings page, they have multiple iCloud accounts. I'd like to delete all of these and only use the one I setup for them, but I can't figure out how to delete these accounts from the device. Or, is it possible for me to add one of these accounts, which are already listed, to my Family Sharing account and then delete the others? Only problem is, I can't figure out how to delete these iCloud mail accounts from the device.

I know this must be confusing to understand, I use Android, so I've attached a couple of pictures from the settings screens that I'm referring to. Hopefully this will help me explain it better so you understand whatII'm trying to do. Thanks.

<Images Edited by Host to Remove Personal Information>

I believe I did that, and the only alternate email address listed under my primary Apple ID is another email address of mine, which I guess is used for password recovery. I get the feeling that they may have got their own apple IDs, but these aren't connected to mine under family sharing. If this is the case, would I need to figure out what their passwords are, then login using the Apple IDs I didn't create, and if so, is it possible to delete these apple IDs so they're not associated with their devices anymore? Would it be easier if I went into settings, reset the settings, which hopefully, would get rid of any accounts linked to the device and then I can set them back up using my Apple ID and then add their's from the family sharing plan?

Well, when I login to my iCloud account, there aren't any alternate email addresses listed. I tried to enter my work email address, but it said it was already linked to another account. I don't think it's linked to another account, but it is listed under the security tab in case I forget my password.

I have no idea how to get these accounts de-linked from these devices, and to top it off, somehow my email address was listed under just about every contact in their phone, which is only a few, but it make things more difficult to setup a family sharing account.

Ok, I'm attaching some pictures from different devices. One is what I see when I'm in General Settings, then one from iCloud settings, then a picture of what I see after I click on Family Sharing and a pic of each individual Apple ID included in Family Sharing. Also, assuming I can attach all these, a pic of each one's mail settings and the Apple IDs associated with Mail, with the App Store, and Facetime. I assume my Apple ID needs to be associated with the App Store, but their's would be associated with Mail settings. Under their Messaging settings, I'm just using their phone number, but it was more difficult when they only had an iPad Touch.

Instead of attaching all of these snapshots, I've uploaded them to a Dropbox folder and here's the link to access them:

https://www.dropbox.com/sh/bhpqxjd40afquif/AABNo4n_wMd2GDNIc_Mt7rlPa?dl=0

Yes, I turned it off.

In the iCloud settings, it's turned off. Now, when I go back to General settings, then Mail, Contacts, Calendar settings, it lists 2 accounts (iCloud, which brings me to the iCloud settings page again, and it also lists their iCloud ID separately. If I go to the iCloud settings, then Advanced/Mail, it still lists all of those other accounts as well, but if I go to the Mail App itself, the only mail account listed is the one I setup under Family Sharing.