The girl who you were trying to protect in Bioshock 2 was named Eleanor Lamb who was being groomed by her mother to become a messiah for a communist utopia.
Here we have Elizabeth who is being groomed by Comstock, her "father", to become the messiah for his American Christian Fundamentalist utopia and is referred to as the Lamb.
In B2 Eleanor looks to Delta as a father figure while she is in opposition to her biological mother and even calls him 'father' whereas in Infinite Booker is literally Elizabeth's father and is opposed to Comstock who is not actually her father.
So going by Elizabeth's statement there there is always a man, a lighthouse and the two of them it fits that in the Bioshock 1/2 universe Booker and Elizabeth's equivalents would be Delta and Eleanor.
Also Booker Dewitt's initials are BD which could also stand for Big Daddy.