Final answer:
The information provided does not state what Amanda did on the weekend; therefore, it is not possible to accurately answer the question based on the given references.
Step-by-step explanation:
Based on the information provided, there is no clear answer about what Amanda did on the weekend. The references given relate to other people's activities and do not provide specific information about Amanda's own weekend activities. Consequently, without explicit textual evidence about Amanda's actions during the weekend, it is not possible to determine whether she visited the Natural History Museum in London, went to a café on the Thames, had lunch with her brother, or went sightseeing in the afternoon.
The references include various activities done by other characters or general suggestions of what to do, such as visiting universities, drawing a map, and spending time after school. None of these references directly mentions Amanda's weekend activities.