Need help determining precisely what is meant by "covered by a retirement plan at work" for a part-timer with income from multiple sources, 99% of which is NOT covered.

Can I set up a nondeductuble IRA for my wife if she had just one day of covered employment in 2019?  We are income barred from Roth IRA contributions, so I am investigating a nondeductible traditional IRA for her and then a Roth conversion.