This 16 yo is the reigning US Open Girls champ and already the second-youngest player in the WTA top 100 rankings as of mid-2018. She's already beaten a top 10 player, Petra Kvitova, and won the ITF Abierto Juvenil at only 14. Strong, aggressive return of serve, and ferocious forehand. Shows a precocious ability to solve problems on court and variety.
Here's a slow motion video of Amanda serving to the ad court during her match with the eventual San Jose MSVC champ, Buzarnescu in August, 2018. Click to play the embed from YouTube, then click the white box that appears in the lower right to expand. Look at her extension and the long-axis arm rotation.
Motion strikes me as smooth and repeatable. Already a decent server, I suspect that with this solid a foundation she can become much more effective, particularly with her second serve. Please click to play.