If you have the wherewithal for something, you have the means, especially the money, that you need for it. She didn't have the financial wherewithal to do it = means. the wherewithal to do sth the money, skill etc that you need in order to do something = means (wherewithal (16-19 centuries), from where + withal)
out of, or by means of which; "tools wherewith to scrape the windshield of my car"