We know that p=mv,
So Sophia travels at 7.2 m/s and she has a mass of 47kg so her p is: p=7.2 x 47=338.4 kgm/s
Neesha travels with a velocity of -4.8 m/s and she has mass of 68kg, so her p is: p= -4.8 x 68= - 326.4 kgm/s
Pinitial=pfinal
ps + pn= mfinal x vfinal
338.4 +(-326.4)=(47+68) x vfinal
12= 115vfinal, vfinal=0,1m/s
As our velocity is positive, the direction is right.