She is checking out each option’s interface.
Head to head between these two browsers rarely changes any minds. In terms of the interface, you can easily customize Firefox‘s web browsing experience more than any other browser, including chrome. Firefox has the ability to install themes and that can fully change the appearance of the browser; even to a point of emulating chrome.
A Feature like Tab groups is among the many features Mozilla absolutely nailed, both in execution and vision. In chrome, you can only get such features through extensions. The differences and similarities in terms of the interface between these two browsers are significantly more or less the same.
It is up to you decide which is which.