She will have Death in Service - whereby she dies you get £xxxxx.
Never heard of a company giving someone money if their partner dies, so fair play to your company. But you would be entitled to both as they will be different plans, so you would get your 5x and her 4x salary.
The redundancy package im guessing is an ASU plan? (accident sickness unemployment) so again, if it does have life cover attached you would be able to make a claim on it. So yes, you are over insured, on life cover, but im guessing you dont pay for the death in service. Most companies give it as a employee benefit