After the breakup, Barney never resigned herself to the separation, and made strenuous efforts to get Vivien back, efforts that did not end until Vivien's death.
Barney never resigned herself to the separation. This was after the breakup. Barney never made strenuous efforts. This was after the breakup. This was to get Vivien back. Strenuous efforts to get Vivien back were efforts. These efforts did not end until Vivien's death.