I know a man who worked at Starbucks, raised 5 children on that salary, and his wife was a stay at home mother.
Assuming he wasn't the manager, he must have had crazy-mad, lightning-in-a-bottle people skills, to get tips large enough to support his family.
There are some people who can pull it off. I knew of one man who worked as a waiter and did very well with his tips, because he just had that certain something.