10 attempted tries on iPhone passcode?

My sister gave me her iPhone 5 and she can't remember what the iCloud password is and I can't do a system restore without the password if I try to disable the iphone, after 10 tries will it delete all of the content or will icloud still be on there?

It won't delete icloud just the data on the iphone.

Nothing will be deleted. You need to recover the password if your sister does not remember. The phone will ask you if you've forgotten your password if you keep on inputting it wrong, and will send you to a recovery page that will send a recovery link to your sister's email. You can probably do the same thing from Apple's website as well.

If your sister gave you her iPhone for you to keep you should just go to the settings app then general and press reset.

That will take it back to what it was like when new then set it up from scratch with your own iTunes account and get the apps you want.

If you use hers it will be linked to her account and every time you need to do updates you will need her password. If she is also using her account in another apple device it will be linked which you probably don't want.

She can get to her iCloud account on any computer or mobile device with Internet so let her figure it out later with the I forgot my password function.