My husband is also a decendant of a Francis and Ann Creegan living in Salford, although we have Ann's maiden name as 'McCrickett' from their marriage certificate. We have Ann's father listed as Thomas McCrickett.
They had a daughter Catherine, so I am pretty sure they are your Francis and Ann.
Catherine's older brother Philp, born in 1870, married Ellen Egginton and had 11 children. One of these was Ellen Creegan, who married Stephen Glynn. They had a son, also Stephen Glynn who was my husband Phil's father.
There are Glynns from this branch of the family still in Manchester, but we don't know of any Creegans yet.
If you would like any more info please get in touch!