Wiping Old MBP - Is everything backed up?

Hi, I will be wiping my old MacBookPro and giving it to my wife to replace her 2011 MBP. I want to ensure that I have removed all my files. I have been using DropBox and iCloud only for Photos and some other apps since I moved a ton of files from my old Windows machine that I still haven’t sorted.

My question is I looked at each major folder Documents, Pictures, Movies and compared to the DropBox folder by copying over to see if anything was not there. Once doing that I deleted from the Mac folders. But when I check the All My Files folder I see my files, I’m assuming this also looks to my DropBox folder? But wanted to know if there is a way to confirm before wiping the laptop for my wife.

I know this is really basic for you but any help would be appreciated. Thanks.

Create a new user name for her, and delete your user account from the Mac.