You are correct about L. P. Dinsdale and Martha Birch marrying in Burnsall Chapelry in Conistone in Yorkshire, Eng.
And yes, the descendants you also have correct. I don't know any more about Martha (also Mary) Birch. I have her birthdate as 1816 in Yorkshire. L. P. was born in Hubberholm, Yorkshire. They had a total of 7 children: Jane, Elizabeth, James, Mary, John, Ellen and Alice. James is the father of George James Dinsdale.