Thank you for answering our questions. While we're on the subject of what we should do with our hands during Mass, I'm wondering if we should be gesturing when we say "and with your spirit, " in reply to Father's "peace be with you? " Thank you again!
It is commendable that you wish to particiapte fully and properly in the Mass. Please don't get too hung up on the exactness of your posture and gesture. That gesture that you you refer to during the words "...and with your spirit." is not called for in the Missal or the GIRM. It is also not prohibited.
Below is a link to a document published by Adoremus which describes every gesture and position that is defined for the faithful during the celebration of Mass. You may find this useful. God Bless.