In this case we will use the general equation:
d = s t (distance = speed*time)
Therefore
Distance Amy can run in 13.4s:
d = (100m/14.1s)*(13.4s)
d = 95.04meters
Headstart needed = total distance - distance run in 13.4s (time Maya runs 100m)
headstart needed = 100-95.04 = 4.96meters