If you are the single working member in a family after a certain size, you may still qualify for SNAP. Usually, not only in the US, but in most countries with similar well-fare programs, the eligibility is determined by the household income, not the individual.

Also, Wallmart have plenty of non full-time jobs, which tend to attract a lot of single mons that have no access to child-care, and this probably increases the probability of those employees being eligible to SNAP.

The media loves to drop those kind of number without context for page-views.