Ah, but you need to be careful of this. Look at how the QS Employment Outcomes score is calculated. It adds together two metrics:
Alumni Impact: Measures whether a uni has produced grads who have gone on to "make a significant impact in society". They analyse a database of 80,000+ “impactful graduates” across business, politics, higher education, and charities, then attributes those alumni back to their universities
Graduate Employment Index: defined as the percentage of grads who enter paid employment within 15 months of completing their degree. Grads doing voluntary work, further study, or unavailable for work (e.g. because of military service, disability, travel, or caring responsibilities) are excluded.
The first indicator will be heavily skewed by past employment practices (such as the "old boys network" and non-uni-blind recruitment), not by present employment practices.
However, even without that, you should also ask yourself whether those impactful people got to where they are because they went to Oxbridge or whether they got to Oxbridge because they were impactful people.
The second indicator is the important one, so you should look at that independently. It comes from Gov.uk open source data here: https://explore-education-statistics.service.gov.uk/find-statistics/graduate-labour-markets/2024 and it is the same data that is included in UCAS course listings. When your DD decides which course she wants to do she will be able to compare the graduate employment data for that specific course at different unis of interest.
The government data comes from an annual graduate survey (15 months after graduating) and distinguishes between percentage of grads employed in any job and percentage of grads employed in jobs commonly related to their course of study. The latter is a very rough measure ... clear cut for Medicine degrees, less so for English degrees. Its not clear which of those has been used in the QS measure.