Anybody that already has had a computer for 2 years and is coming from Windows will have almost no problems with Mint. Stability is top priority for first time Linux users and you need some visual guide with screenshots. Mint also has a great default look and setup for people coming from Windows. Mint is probably the best distro to put on your mom’s old laptop that is “getting slow” because of viruses.
I’d recommend KDE Neon or Ubuntu also depending on the situation but if I don’t know anything about the person and computer I’d say Mint.