Tough - huh?!?! I went to the trouble of finding out about the quality of the engineering department at the time that she undertook her degree. My comment about 'does it matter' was more to do with what does it really matter in the context of her life, her career and the the decisions she has made whether her degree, which was obtained over 35 years ago, was a 'good' one or not? It's probably a judgement call. You'd need to look at the overall transcript to see how she ended up with a third. You'd need to look at the supporting reference her tutor provided. With a reputation as a strong engineering department, if I had been looking to employ her, I would probably give more weight to a third from Cambridge than a third from another university. But whether it should be given more weight than a higher class degree from another university is unclear.
Can I go back to trivial matters now?