Hello Again, Could it be that one of you is logged into a Google account and the other not? If so Google customizes search results based on your history. In fact, even if you are both logged in, Google could be showing different results just because of the different history.
If both of you are not logged in, I don't know. I just know one time when I was doing some optimization for a site I noticed that the site was number 2 in Google extremely ahead of my schedule. I started think no it can't be there so soon. So I pulled out my phone and search with it, sure enough the website was on page 4. It turned out that on my desktop I have customized search turned on and being that I was working on the site so much it saw my history and ranked it higher. I jumped into settings and turned customized search off and sure enough my website was right where I thought it would be, on page 4.