Help on Mechanics for Obstruction

[Bagman62]

Situations.
ASA 18 U. R1 on 3B,Passed ball, Catcher moves to backstop to retrieve ball, Pitcher move to cover plate and R1 runs to Plate. Pitcher arrives and blocks plate with her leg prior to catcher picking up ball. R1 about 15 feet away from the plate

Catcher throws ball to pitcher, R1 slides around Pitcher as tag is applied foot hits the plate.

QUESTION, When do you signal Obstruction as the sequence is: Block, Catch & Tag... ASA rule for 2004 Says Catch, Block & Tag. Question #2 do you call Obstruction on this play?

Thanks for the information & assistance.