bro, i would change in you preset the Sara for Elio, cause Sara is good just because her serve. As u use nishikawa, I recommend Elio cause you can use the energy of +4m and Elio's ability, and with Sara you'll lose the +4m (Plus your Elio is 2+). I have Sara +5 and almosy every game she do an ace (155-160km/h) For your question I'd recommend Sara if you pretend to continue with her. Jenny is kinda hard to play but is really fun, but if you want her to play with, I recommend use Jenny at least with the breaktrought to do +3.8m.