Apple ID's and Two Individuals

Question

Not sure if this is the right area for this, but here it goes:
My partner and I have both had iPhones for years.  I have had an AppleID since day 1 and use all apple services and have Mac computers.  We both have iPhones and up until recently, just used both almost identically, and actually she barely used any services.  But now she has an iPhone 4s, and I have an iPhone 4... she wants my password to my AppleID so she can download apps etc.
The ISSUE.
With my password basically she has full access to my account, which could potentially mean getting into my email, account etc.  I recently changed it so that its not my universal password and gave it to her.  But I am still not cloud syncing her phone because she has seperate contacts and calandar events that should not merge with mine.
The QUESTION.
How do we both have seperate accounts on two phones, where we can buy our own apps with our own money.  Our own songs and other content as well, but at the same time, share all our content?  I'd like her to be able to cloud sync and have access to all apple features etc, but dont want her synced with my contacts or have access to my mail etc.
Is this even possilbe?
I was thinking you could have seperate 'users' under one iCloud account, but I dont see any options on icloud.com to add or do anything.
Thanks in advance.
Any and all help giving would be great, sorry its verbose, but I dont want a quick answer like 'make her an apple id' which doesnt answer my question.  Also I have nothing private she cant see, but I just dont want our stuff merged.  But we have both purches our libraries together and equally own everything.  We do of course both live in same household and are a 'family' (i.e. girlfriend of years).

Answer 1

You can't do exactly what you want, but you can sync your own email, calendars contacts etc etc but both still have access to the same iTunes account.
Firstly the Account for the iTunes store can be different than the one you use for data syncing, so in that sense you will be able to keep your information private as you want.
You can also of course each have your own iTunes store account which would mean you use your own money to purchase music, video, books, apps etc etc, however you can not then both use each others content (you can homeshare music) and at least one of you want have any access to any purchases made before the split.
You might consider an Apple ID each for iCloud sync services, but make the best of the situation with iTunes content.