You do not have to disconnect your PC from the router to connect your wife's, just plug both in at the same time. You do not plug into the router via USB, there will be an
RJ45 socket somewhere on the laptop and, in fact, most routers have four. If your wife's PC is running a legitimate copy of Windows 7, and I am not suggesting for a second that it is not, then there is no reason for it not upgrading to Windows 10 other, of course, than some technicality - personally, I have been involved with upgrading three PCs, I know I mentioned two before, and not one did it without problems and, when you get problems, you just need to go looking for answers until you get there - worked for me anyway. At this point, I should stress to you that I am no expert, just someone who is happy to try to find the relevant answers.
I must say I do not use Roboform, Chrome or Edge so can offer no assistance there.
And finally, I do not know your wife and can definitely offer no assistance there.
Martin.