So I've looked at several biographies of Rosina, Edward, and Rosina & Edward, and I still have nothing but the most basic of timelines. Here's what happened (probably):
Rosina and Edward met in 1826, when both were about twenty-three years old. They were married in August 1827, over the objections of his mother. Their first child, Emily, was born in June of 1828; their second, Edward Robert, in November 1831. In 1833 they went to Italy. In 1836 they were legally separated, and she was given an allowance of £400 per year for his lifetime, plus £50 per year for each of the children for as long as he allowed them to stay with her. Two years later he took custody of the children. In 1848, their daughter Emily died of typhoid fever. In 1858, Rosina denounced Edward publicly at "the hustings," a political event at which he was speaking*. As a result, he had her committed as insane, but she was released three weeks later. He died in 1873; she died nine years later in 1882.
So far so good. The problem is that none of the biographies seem to be able to agree on anything else. The trip to Italy provides a perfect example: Edward's biography claims that the trip to Italy was taken on account of his health, while Rosina's biography states that he went in order to convince her that he had ended his affair with Mrs. Robert Stanhope, when in fact (according to Rosina) it was all a trick – Mrs. Stanhope and her husband were traveling on the same boat with them, and he continued his affair in full view of both his wife and Mr. Stanhope. Not only that, but most of the biographies I've looked at list the same sources as the ones I'm using, which means that they don't know any more about it than I do. They're just speculating.
*What is a "husting"? Glad you asked. Wikipedia has a nice definition and etymology, which you can read here.