Which preposition to use with robinsons

after Occurrences 1%

The same warmth of heart and disinterested friendship appears in his efforts to re-establish the affairs of the Robinsons after the failure of that firm.

at Occurrences 1%

He had been tutor for two and a half years with the Robinsons at Thorp Green, in the house where Anne was a governess.

for Occurrences 1%

"You need not light the gas in my room, Mary," she continued in the same tone of voice as the door closed upon him; "I shall lie down for a few moments, and then I may run over to the Robinsons for the evening.

Which preposition to use with  robinsons