Mona needs to use her knees and her body more when serving. In that vid you yook her service action is all arm.
Hope her mum recognizes this
Also she still has not learned a proper kick serve. Her second serve is still all slice and drifts to the forehand of a righty. Pervak's backhand is pretty good so I guess that was a factor, too.
She has to flick her wrist from bottom to top when making contact with the ball, right now she is slicing it from right to left and that's what she's been doing for ever now. I actually once wrote her an email and her mum replied nicely thanking me for that advice and saying it was tough for them to find a coach (I wonder why??!