There are different rules for traditional pre-tax IRAs and Roth IRAs.
In both cases, she can contribute up to $6000 (or $7000 if over age 50), or up to her compensation from working, whichever is less.
For a Roth IRA, contributions may be reduced or not allowed based on filing state (married filing jointly or separately) and overall income. It doesn't matter if part of the family income is from a pension, just the amount of income.
https://www.irs.gov/retirement-plans/plan-participant-employee/amount-of-roth-ira-contributions-that...
For a traditional pre-tax IRA, contribution limits are affected if either spouse is covered by a retirement plan at work. Receiving a pension is not "covered by a retirement plan at work" because that person is no longer working. Receiving benefits is not the same as being covered by a benefit plan. So you would use the income limits at the link for "not covered".
https://www.irs.gov/retirement-plans/ira-deduction-limits
