At the 2012 Summer Olympics in London, Blume competed for the Danish team in five different events. In the 50 metre freestyle she failed to advance beyond the heats having finished 8th in her race and 26th fastest overall. In the 100 metre freestyle she again was eliminated in the first round after finishing 6th in her heat and 19th fastest overall. She won her heat of the 200 metre freestyle but did not advance to the next round after finishing 24th fastest overall. In the 4 × 100 metre freestyle relay Blume swam in a Danish quartet along with Mie Nielsen, Lotte Friis and Jeanette Ottesen; they qualified for the final, in which they finished sixth, setting a new Danish national record of 3:37.45. In the 4 × 100 metre medley relay Blume, Nielsen, Ottesen and Rikke Pedersen reached the final and finished seventh. Later in 2012 she won a gold medal at the World Short Course Championships in the 4 × 100 metre medley relay. She also won a bronze medal in the 4 × 50 metre freestyle relay.