Well, your sister (and friends & relations) will have my prayers that she returns to the faith. I do know you are passionate in your defense of the faith... and I realize the lies must be countered with the truth. Please do not think I'm asking you to "chill-out," I'm asking you to look upon this mission as something joyful...Thank the Lord He has seen fit to give you this calling! Pace yourself, and do not become angry. Fight the lies with the tools God has given you (and they are many).
It's my sincere (and humble) belief the way to fight the lies is with humor and compassion (note: I did not say 'tolerance.') Let's let Jesus be our guide in this crusade...He challenged the lies, rebuked when needed, and sought to educate... He did not become angry with those in need of His Salvation.
May His peace be upon you. :o)
Reading what you two so eloquently state, not only on this thread but many others I've "lurked" on, lets me know it was the right decision to come back to the Catholic Church.