It sounds like the core of this hack was an attack on her email (followed by password resets for registrar, etc.). So the #1 step to reducing your risk of an attack like this would be setting up 2FA on your email account. The industry standard is password resets via email. If an attacker has access to your email, they have access to every online account you own. Stealing email passwords is easy. So easy. No matter ho…
And step #3 is to keep all your softwares up to date; OS, antivirus, browser, your WordPress, its plugins, your Notepad++, WinRAR, firmware of your ADSL modem, other computers on the network, BIOS, smart TV etc. Everything should be updated to the latest version.