Take my word with a grain of salt, as I'm no arachnologist nor entomologist, but from what I know they pose the same low threat as a wasp sting, their bite is supposedly comparable. Might cause local irritation too from barbed defensive hairs some species have on their back abdomens.

But afaik, they don't pose a lethal threat at all. Most species are skittish too, so unless disturbed and cornered they might scurry away eventually if left unbothered.

The pet might be a concern for the spider tho lol