The only thing I ever really leave home with is a padlock and a key for the dingy.
2 fully-charged cellphones / mobile phones (on different networks)
Money - including coins for parking, Credit card, pen, paper
AA card (that's automobile association, like AAA - not Al Anon)
Tissues, brolly, anorak
.. and round here at this time of year
wellies, snow brush / ice scraper, snow shovel, road grit / salt, hat, gloves, fleece
If she's going to actually "leave home", then she should pack a large trunk of all of her clothes, plus copies of bank account numbers and credit card numbers, and a copy of her divorce papers.