I deleted my facebook app and messenger app on my ipad to secure that my daughter will not use these app, but I cant install these apps now,what should I do?

You shouldn't do. On iPad deleted apps will disappear from the tablet but a copy will still show as saved to your account when you view your apps through iTunes. This prevents apps you've paid for needing to be bought again if accidentally deleted.

Regardless of this though, even if the app were permanently deleted a copy of the app data such as content & settings should be preserved to support any future reinstall.

Double click the home screen and kill the facebook app and the facebook messenger app

Then try reopening both applications.

1. First of all, you must have messenger app to open your messages
2. try closing the app, restarting your ipad & re-open the FB app again.
3. Uninstall app & install a clean version again
4. if above didn't work; you can use safari to open your FB account as if you are opening it from a desktop/laptop

go back to facebook an re add the app

Delete the Facebook app from your iPad (press on its icon until it quivers, tap the X to delete it, tap the home button). Then, open the App Store application and tap Purchased. Find Facebook and re-download it. You'll be asked to log into Facebook with your user ID (email address?) and password to continue.

Get your daughter to go into her Facebook account.
Ask her to go into account settings. You will find an area that allows you to sign in it of ALL devices.

This should disconnect her Facebook account from your iPad.
Uninstall the Facebook app. Soft reset the device (power and home button) then reinstall the app when it comes back on.

Let me know if this helps.

Find the icon for the app you want to delete, and press and hold it for a few seconds. It (and all the other icons on the screen) will start to wobble gently, and a small cross will appear in a grey circle by each. Tap the cross, then confirm you want to delete the app.

Search the app Facebook on ipad, delete the old app if there is one.
Reinstall a new Facebook app on your ipad via app store.

If you are talking about facebook messenger you just need to hold down your finger on top of the icon, wait for it to shake and a little 'x' button to appear on the app icon, then click the 'x' button. If you are speaking of the Messages app for the iPad, I'm sorry but that can never be deleted. Hope this helped!