Question on migrating from Google Services to Microsoft Services

So my wife is changing email addresses and ended up getting a good one on Outlook. The problem is she wants to keep things pretty simple, meaning one service ecosystem at any given time (she doesn't want to need to remember where she needs to log in to access what information). Most of the transition to Outlook was easy enough. I exported her contacts and calendar from Gmail, and imported them to Outlook. I stopped her photo auto-backup on Google+, and set up OneDrive to back up her photos.

But then I got to Google Drive and her documents. We collaborate on a lot of documents and spreadsheets for finances, checklists, etc. and I'm wondering if Microsoft has an alternative. I have an Outlook account that I maintain, but it isn't my main address. Is there a way to collaborate on our spreadsheets using OneDrive and Office Mobile? OneNote? I know I can open and edit Word/Excel files in a desktop browser (similar to Google Docs) and figured collaboration was baked in, but I'm not seeing an option for this. If it's not there, then it's pretty much a deal breaker, which would be unfortunate since she's stuck with a rather crappy Gmail account name if she needs to stay with Google. A quick Google search didn't look very promising, but maybe I'm not looking in the right direction.

Anyways I just thought I'd ask here before throwing in the towel, since I'm sure most of the Tribe are more knowledgable on this than I am. Thanks in advance.

I should note that she is on Android (for now) and I'm on iOS, if that makes any difference at all.