Howard Case's widow was the former Elizabeth Crowther; they had four children - Helen, born in 1890, John C., b. 1892, Charles E. (or J.), b. 1893 and Honor Elizabeth, b. 1894. Helen was born in England when the Cases were residing in Toxeth Park; the latter three were born while the family lived in Rochester, NY prior to relocating back to England.
As far as I've found, the surviving family returned to the states in the summer of 1912 and lived briefly in Mrs. Case's native Baltimore, Maryland before returning to Rochester. Elizabeth died in 1939, if I recall correctly. She was buried next to her parents in Cockeysville, Maryland and Howard is memorialized on her stone. I visited the grave back in '98, but at the time I wasn't that interested in Elizabeth's story so unfortunately I didn't take notes on her or her parents.
Here's a picture I took of the grave, though it leaves much to be desired (Imperfect lighting, imperfect photographer, etc.) The inscription for Howard reads:
In Memory of Her Husband
Howard Brown Case
Died on Titanic April 15, 1912
Aged 49 years.
I do not know what became of their children in the long run, though the 1930 US census indicates that John followed in his father's trade.