Retirement tax questions

Thank you for the kind, thoughtful and very prompt reply.

Yes, I understand the deductible/nondeductible issue and the income limits.  My concern comes to the filing of the tax return when a single question is asked, if this is how it works, is she covered by a retirement plan at work?  For one job, yes.  For the other three, no.  As I understand it, she is not eligible to make a traditional IRA contributions if she is covered by a retirement plan at work.  I am covered by a plan at work.  Thus my question.

She has earned more than $7,000 in 2019 from employers without a plan and we are between 50 and 70.  She has earned precisely $100 from an employer with a plan (one day of substitute teaching).

I do not expect tax deductibility.  I just want to be certain she is eligible to fund a traditional IRA in 2019 with a nondeductible contribution.  If yes, then we will do this and immediately convert it to a Roth.  If not, then we wait until next year and re-evaluate.