Thank you all for your replies. They have helped to clarify the relationships.
I think that Phoebe is the Daughter of Edward and Mary who was previously married to Joseph Ferguson. and that mary's daughter from the ferguson marriage married Joseph Wilmot.
Phoebe's siblings are ?, Sarah h, Mary, William, Daniel and Thomas.
The baptismal date of 14 April 1844 sounds correct for Phoebe but The parents given as James and Mary is somewhat of an anomaly. There is no birth record on FBMD.
There does seem something suspect about Mary's age
Thanks again for your help
Julia