Retirement tax questions

The retirement plan box on your spouse's W-2 should be checked if her employer has a 401-K plan that she is eligible to participate in, even if she chose not to, and even if she is part-time. You may need to re-enter the W-2 to get it to populate properly after you delete the retirement plan box entry.

Your contribution amount may be limited by your income since she is technically a participant in a retirement plan. You can learn more in this IRS article.