I remembered watching Zacarias a year ago against Abanda in the finale of a junior tournament. I thought she looked so good, great consistency but also aggressive when necessary. Sad to see she hasn't made any progress.
I remember her beating Rezai a couple of years ago making people $ happy.
I think being from a tennis development country like Mexico has a lot to do with this. I have also noticed that the geographical background for that matter is likely to decide who of two equally talented players will have the better career.
If you look for instance back at the junior world championships in Biathlon a couple of years ago you will find quite an amount of Romanian athletes in the Top 10, even on the podium. Needless to say that none of them was able to fulfil his/her potential. The training facilities are a catastrophe.
It's the time between juniors and seniors where this aspect plays a decisive role.