Saniya's 3 pointer is much like Tiff's in that she shoots it from a low position. It is blockable once opponents realize they must defend her. To date they are laying off of Saniya as much as they are off of MoJeff. Remember after she made those first two 3s the defense changed and we did not see any more. Reports are that MoJeff makes her shot regularly in practice so it is likely it will come along in the game, too.
Opponents cannot play very far off of either MoJeff or Saniya because doing so leaves them vulnerable off the bounce. Playing off a little helps but not playing off as far as cheat help defense requires. Both will exploit anyone attempting to lay off too far of either. Both, also, go very well to left and right and with the current emphasis on touch fouls before will go to the line frequently with anyone who tries to impede them at speed while recovering. Finally, both shoot their free throws very well. Geno has an embarassment of blessings in these two.
But unless MoJeff further sprains her ankle or cannot go for another reason Saniya is not replacing her as the strating PG.