Emily (Derby) Crosier

Emily Derby-my gg grandmother- is one of my dead ends. Crosier family lore has birth in Hawley MA to Alvin Darby and Mary?. Based on her age at deathshe was born 15 Sep 1812. I have found probable sibs: Martha Derby Porter who was a witness at Emily's wedding and Alvin Derby Jr. Alvin Sr based, on census records, moved about western MA and used Derby and Darby. Lore says he was from Clarksburg MA. Would appreciate any data on Alvin and Mary. Thanks.