Emily Dickinson's poem, "If I can stop one heart from breaking," provides a clear insight into the kinds of things that the author genuinely cared about. Though she traveled very little from home, Emily Dickinson had a remarkably perceptive view of the world—a world which inspired her beautiful poetry.
If I were looking for a thesis statement regarding this poem, I would study first to the main points of Dickinson's verse.
Her focus is on three things:
If I can stop one heart from breaking...
If I can ease one life the aching...
Or help one fainting robin / Unto his nest again...
In these three lines, we see that Dickinson concerns herself with a wide variety of interests: she looks to nature, she refers also to one's breaking heart, and finally, she concentrates on the quality of a person's life.
Because Dickinson does not list these things from most important to least important, we might assume that to the author, all three are equally important in her eyes. She also tells the reader that her own satisfaction comes from helping others: that another's wellbeing is enough to not only make her feel happy, but to provide her with a sense of personal value in life. The concept that seems of primary significance is that helping others, if she can, will be the most important legacy she could leave behind when she dies.
When we stop to consider these things, this seven-line poem says much more than we might notice at first glance.
With all this said, my own thesis would have to reflect the sense that Emily Dickinson placed a higher value upon the wellbeing of others, rather than her own personal satisfaction, which shows her to be generous and selfless in her desire to see the world a better place.