A couple of issues to consider:
1. What will be the tax-free lump sum if she retains the DB rights? If she opts for the TV (and transfers into a PRSA say for say 6 months) then she can take 25% as a tax-free lump sum. Maximising the tax-free element is normally advisable (though your combined tax rate on income is also a factor, whether 20% or 40%).
2. Simply comparing the €22.3k income to the €585k TV, it equates to an annuity equivalent of 3.8%. However if you were to buy an Annuity from age 60 with say 2% indexation (for a female) the Annuity rate would be c2.4% (so you would need a TV of c€900,000.
3. if you opt to retain the DB, then you need to consider how secure the Fund is? Is there any risk that the main scheme is underfunded and that the DB might be reduced in the future if the Scheme was wound-up. This assumes the DB income is paid out of the Fund (as opposed to the Scheme buying an Annuity with a Life Office - a more secure option for you wife).
4. if you opt for the TV , take 25% as a tax-free lump sum, and invest the balance into an ARF (ignoring the need to put some of the residual into an AMRF), then you must draw down an income of at least 4% pa, so c€17,500. But if you invest into an ARF, then you have to consider investment risk (a low risk, or medium risk strategy). And depending on the fund performance, the 4% drawdown could result in a gradually reducing income over time.
5. Finally, she should consider the health/longevity risk. If she is in good health, has good family genes, then her average life expectancy at age 60 is c27 years. That would incline one to opt for the DB. If however she is not in good health, not good family genes, then maybe the TV looks more attractive (a bird in the hand etc).
6. Since the DB has no attaching pension paid to a surviving spouse (on her death in retirement), the TV/ARF has the attraction that on her death, any remaining funds are not lost (can form part of estate). However for a female/male combination (and assuming male is say 2 years older), the odds are that the inheritance by a spouse is unlikely.
7. Finally, other assets need to be taken into account. Does she (both of you?) prefer the relative security of a guaranteed income (the DB) or would she prefer the flexibility of the ARF route.
Hope this helps.