Formula for the height is:
h = v i · t - 1/2 g · t² ( minus sign because the gravitational force is in the opposite direction then the force that a player exerts )
0.411 = v i · 0.625 - 1/2 · 9.81 · 0.625²
0.411 = 0.625 v i - 1.916
0.625 v i = 0.411 + 1.916
0.625 v i = 2.327
v i = 2.327 : 0.625 = 3.72 m /s
Answer: Her initial velocity was 3.72 m/s.
