I think I'm grinding to a halt with my research and desperately need some help!

From some legal documents I have partial information as follows:
Peter RIGBY (died 1707-1737).
His second son was James RIGBY (1675ish-1740/45) who married Ann MARSDEN in July 1700.
Their children included Peter, Jane and Mary. (Mary married Ralph STRETTLE)
Peter, possibly married Mary SEED and his children were Ellen (m. William MURROW 1756), James (d. 1824), Robert Marsden (1756-1838), William (d. 1836), Jane (m. John ATHERTON 1766), Thomas (~1743-1842).

Robert Marsden RIGBY is my direct line which I have managed to follow through. Please can anyone help me with further information about his siblings and/or the previous generations.

Thank you.