You are absolutely correct about Tam. It's the old cliche... ...You can lead a horse to water - but you can't make him drink.
She was very obvious that she wanted to go on this trip...to post it on his desk calender, then wanting to leave it open on the day of the trip...it is her way of controlling the husband... thinking that "this trip" will solidify the marriage. Just like the last trip...but that backfired on her.
I also surmise, that she'll tire of her therapist because she will not be told, what Tam wants to hear...
Sometimes, people need to hit rock bottom and lose...before they are willing to learn.