ClamAV is probably the way to go. While there are UIs available in various states of maintenance, it's not really necessary. The way ClamAV works is that runs a scan on daemon (re)start then continually monitors the system from there. One of it's best features is that you don't really need to worry about it.

An antivirus is mostly unnecessary when care is taken to not install or use untrusted software. If you install everything as a Flatpak (and modify some of the default permissions), you can avoid allowing software to gain much access to her computer.

While I think people suggesting Linux is immune to malware is stupid, for reasons such as it is "too secure" or "too niche" to be effected by malware, anti malware is like a bandaid to a gaping wound. If you have malware, it is already too late and you should first unplug the device from the network and any connected devices, backup any important data, and fresh reinstall by overwriting the infected install.

If you still think you need some way to defend against malware, use the VirusTotal website, or a native Flatpak called Lenspect, to upload and scan files (such as an executable binary). Lenspect requires no permissions other than network access, so it is safe and the only risk is if you input a file containing personal data it will be uploaded to VirusTotal.

Though to stress again, antivirus is a bandaid! The real solution is to be smart about what you install and only take stuff from trusted sources. Try to make sure everything is a Flatpak and avoid apps with excessive permissions, which weaken the security of the sandbox.

Linux viruses for desktop computers are so rare, they're pretty much unheard of in practice. And that's why virus scanners aren't really a thing on regular computers. What we do is protect servers against malware and rootkits. And the Linux mailserver or fileserver will run a virus scan before forwarding the mails to the employee's Windows computers. That's why ClamAV doesn't come with a GUI because it's supposed to run in the background on your mailserver or NAS, not on your computer...

I'd recommend a virus scanner if you run Windows games and software (via Wine/Proton/Steam). Especially if they're not from Steam but (pirated from) random places of the internet. If you run Linux software, ideally from the package repository, there's little to no benefit in installing antivirus due to the lack of viruses.

Pay attention to security though. There's a lot of other nefarious stuff out there. Password brute forcing, phishing, regular fraud, attacks if you don't do updates, a harddisk might fail...

The best Linux antivirus is a healthy dose of dontclickshit.bin.

She’s not afraid of the terminal, but she likes the convenience of GUI programs.

Your wife appears to have the same preferences as I do. I don't mind using the terminal (I usually have one open any time I'm using my laptop or PC), but some things are far simpler in a GUI.

No av on my machines on Linux.

What I understand, av on Linux is used to protect windows.

Use an ad blocker when surfing (ublock origin), install only via official repos and set up a DNS server with decent blocklist and you should be fine.

You might have issues trying to install clamav on Bazzite as it is an immutable distro

Antiviruses are rarely used, I wouldn't install them on a newish distro for a non-tech user. It sounds like it may cause more issues than it will intercept

Kinda mirroring the other points here, if you only install from the distro's repos then you're all good.

But...

Better than AV (blocks known bad), you're better off looking into things that only allow known good, like selinux, etc, which might be part of bazzite anyway? (I don't use it, so unsure)

ClamAV is the thing to use, AV-wise, but it makes no sense to use it and spend resources unless you know in advance you are going to get Windows stuff at risk.

Long-time Linux user, have never run AV on my Linux machines.

A few years back, I was forced by compliance rules at work to install AV on a Linux server and started looking for solutions. I shopped around a bit and what I found was that even the commercial AV vendors who supported Linux had no more than 4 or 5 actual signatures to detect Linux malware, and they were all 5 or more years old.

Things may have changed since then, but this may be a good way to think about it... how much Linux malware can these tools actually detect?

Yes, Linux rootkits are a thing but if your AV doesn't detect them, there's no point running it.

for ease of mind just install clamtk but clamav pretty much runs automagically without intervention.

I'm not sure you really need an anti virus with Bazzite? Because it is immutable and has rolling releases it's generally pretty up to date and secure

If you were running a more traditional distro it might be more of a requirement

No, thanks.

I've been using it since about 1995 and the only uses for ClamAV I had were as a mail scanner for a mail server with Windows clients, and as a file scanner for a Samba server with Windows clients.

If you keep your system up to date, don't install stuff from random sites, and don't run as root all the time, you'll be ok.