Heads up. My wife went through decades of abuse, terrible childhood all around. She's been fighting issues with anxiety for 10 years. She's made significant progress in only the last 2 years. The first 8 years essentially were trying to admit that she had the issue, trying out therapies/techniques that could potentially be effective, and then when they were not putting the recovery on the back burner until another year or so went by and a significant period of anxiety compelled her to move forward again. There's alot more to do in the situation you are describing than you are capable of, just from the standpoint of time alone. Just be cognizant of that when you start to try and measure the efficacy of your efforts...
That's totally cool of you to want to set the stage, just remember it will only happen if both parties agree that there is a problem, agree on what the immediate triggers are, agree to cease committing those actions, allow the ISFJ to enter therapy and guarantee that the ISFJ will not quit therapy, nor the ESTP will not quit ceasing their "trigger" actions until the problems are totally resolved. That is the crux of the issue, based on my personal experience. I wish you and them all luck, seriously. Give it a go, but realize that there is only so much you can do. People change when they WANT to, and that's not always when they NEED to for their own good...
Thank you Halla