FNH has been making quality handguns since John Browning moved to Belgium in the late 1920's
That said, you don't here much about them because they truly don't market themselves. You would literally have to go fire one to know what most are talking about. I've had Glocks, and S&W most of my adult life. And when my gunsmith told me to look really hard @ an FN I did.......I'm certainly glad I did!!! If I could afford it I would buy more now. I even told my local LGS that if FN made a compact 45 in the FNS line-up, it would be a show stopper. Some hate the fact that that there triggers are a bit hard to work or, or have too many parts to them (compared to Glock). Yet they have had one of the the best triggers out there, for a Factory trigger. You still have take-up, but not near as much as other. Very pronounced "Wall" or where it stops & the break is very crisp & not gritty at all, consistent as well. The reset is very good and almost no over-travel. Some "Experts" say they can feel it.......I can't.
NONE of this stuff I ever knew about till I learned it. I've learned from so many people over the years, I am glad I had many around me to help & to learn from.
I have an FNS9c.......IMHO, it has been the best Compact 9 I have ever had in my hands & fired. Even more so than the S&W 9c and the G26 for a comparison. Keep in mind that Both of those are still very good handguns. The G26 has had a track history like no other.......but I really like my FN for sure.
The ONLY striker fire to this date that I have fired (and have) I would rank above my FN is is the HK VP series.......by far one of the FINEST I have ever had the pleasure of placing in my hands.
As far as convincing your cousin that there might actually be something out there other than Glock.....I am sorry, and good luck