One of the biggest problems they have had is that anger is very scary to Henry. Thelma learned to present her issues calmly and without accusing Henry.
Notice that Thelma said she "learned" this skill, and it is likely one of the bedrocks for the longevity of their marriage.
If Thelma and Henry came for marriage counseling, I would teach them specific tools for talking to each other ? and listening to each other -- so each is heard and feels safe in the process. There are precursors to feeling overwhelmed or scared and awareness for that can be learned in order to have the best possible communication.
I would also help them understand that anger is okay; it's how it's expressed and used that makes the difference, and would remind them of Gottman's 5:1 ratio of good to poor interactions for healthy marriages.
I have seen couples however, where one spouse is so terrified of triggering the other's anger that he cowers and is unable to be authentic or share her view of a situation for fear of what is likely to come. These couples must work on anger and communication issues.
Thelma's tips for couples are:
1. Work on willingness to resolve issues ? it may take a while, i.e., over time. But it's well worth it. Notice that Thelma doesn't say "resolve it now," she talks about willingness instead. This is how people stay married. They have a will to do so.
2. Make your needs or wishes known to your spouse ? it's so helpful. He or she may not be a mind-reader. [In fact, none of us are mind-readers, although couples get better at reading what their partner needs. Being explicit is more helpful, and doesn't put the pressure on your beloved to figure it out.