A bit unusual to only allow 1 step as a 12 year old, but not the end of the world.
The key with a one step serve, is to 'pre-load' the serving shoulder. By that, if your daughter is right handed, you want her to start with her left shoulder forward and her right shoulder already back.
Think of a baseball pitcher who is in the stretch windup because a baserunner is on first. This is the look you want your daughter to have (but not quite perpendicular to the net, like the pitcher is perpendicular to home plate).
Instead of her feet/shoulders being 90 degrees to the net, have her left foot be at 75 degrees to the net, which will automatically load her right should back. This pre-load of the shoulder, allows her to use all of her energy transitioning forward to swing when she steps, versus transitioning back and then forward, by facing straight at the net before the serve.
Lastly, when set up at 75 degrees to the net with her right should back, she needs to start with her left foot (forward foot) close to her right foot (back foot); this will allow for a much more effective weight transfer with a solid step. Too many young players start with a wide stance on their serve and take a small step which is does not generate power. Start narrow with the feet and take a big step, which generates power.
I am currently a junior in high school and I have been playing volleyball since I was in the 7th grade. I would really love to play volleyball in college, but I am not sure if I should even try due to my stature. I am 5'4'' and I play as a libero/DS. I take AP classes and I keep my schedule rigorous, and I have a 3.77 GPA currently.
I will be going to camps, and participate in training over the summer, but would I even have a shot at a Dl or a DII school? And what are coaches looking for in a recruitment video?
Can you pass nails and play great defense? Forget everything else; your height, your wingspan, you hair bow color, you preference for breakfast.......Can you pass nails and play great defense?
If the answer is yes, then you can play DI or DII (or NAIA or JC) college volleyball. If the answer is no, then you can't.
Some coaches like taller liberos; some don't care. I have seen great liberos who could almost walk under the net without ducking.
Focus on what you can control versus what you can't - Get your skill sets as elite as possible, use your great academics to your advantage (DII and NAIA package their scholarships (academics/athletics/merit/
need based) and reach out to colleges to say "hey, I am a great libero and you need to recruit me!".
In situations such as yours, I would recommend you take a hard look at NCSA Athletic Recruiting; their Free Site is excellent and their Premium site is the best out there. They can be huge resource to help you reach out, filter and communicate with college coaches.
Motivate the college coaches to come see you, don't wait for them to find you!