I think Anne is willing to cut her cousin some slack because she sincerely believes he's suffered an unhappy marraige and that he has been a bit chastened and humbled by this experience and more willing to listen to the elder generation who'd been right in their judgements about his wife. Anne also thinks that he is angling to be reinstated to the families' good graces in order to court her sister. Then there is the reason that Anne won't admit to herself, that she is cutting him more slack because of his attentions to her.