A number of year's ago, top 10 college volleyball programs started recruiting on just height/potential, believing that they could 'coach' or 'teach' the tall athlete to be a good volleyball player. This had a 'trickle down' effect, with the rest of DI and DII starting to recruit height, and try teach talent. The elite programs could recruit height which had acceptable talent to improve, but the rest of the coaching mortals could only get height and falsely believed they could teach talent!
When the mass of college coaches realized that they did not have the coaching Midas Touch, there were two reactions - 1) Increase substitutions so there is always a matching DS/Libero for the tall player who can't pass or set the ball straight, but can sorta hit, 2) Cut the tall player because she is only tall, and get another tall player who has more skills.
When this first shift in recruiting happened (recruiting tall over talent), many parents/clubs panicked and thought height makes right with recruiting. The clubs did not have to pay the price because they could rightfully say that x amount of players received collegiate playing opportunities, but the families were placed in the rough position of having to manage a daughter who may never, or who got cut through no fault of her own.
It is better to focus upon overall skill improvement and general conditioning in high school age athletics, and how it relates to recruiting success. I get very nervous with any specific jumping or 'speed' program just because as a college coach, I don't want my recruits arriving to campus worn out or injured (which happened way too much - and which is now resolved by the college coach cutting these players). The high school body is still growing and maturing, and to put the stress of a hard core jump/speed program into this situation can have serious negative consequences.
Focus upon improving her volleyball skills, focus on staying fit (eating healthy, getting enough sleep, overall physical balance) and let her DNA take over. Some kids just jump higher than others, and while a jump program will help, it cannot reprogram an athlete's genetic make up. But, it can create enough wear and tear that back issues, shin splints, stress fractures can emerge over time.
It is hard to quantify what is a good improvement for an athlete from freshman to senior year; it is better to keep it relative. As a freshman, was her jump above, the same, below her peers? As a senior, is it above, the same or below her peers? If she is the same or above, that is good!
Again, focus on volleyball skills and general fitness - The rest will fall into place and will occur with a much reduced chance of repetitive stress injuries.
My last piece of free yet extremely valuable advice is to shut down your recruiting thoughts until this time next year. Your Baby is just a freshman and please enjoy this last year of her being a kid before the stress/craziness of recruiting emerges as a sophomore. With all the coaching changes and conference shifts in collegiate athletics, to go hard into recruiting as a freshman is just illogical - It is wasted energy and emotions.