“Tis really very kind in my Aunt to ask us to Bath again; a kindness that deserves a better return than to profit by it.”

I think she is saying they should do something nice for their Aunt? As we saw with the tips (thread below) visiting was not completely free—although I would not equate giving a gift to a relative or friend with tipping a servant. In S&S Eleanor is conscious that she should, and does, accompany Mrs. Jennings on her visits and shopping because Mrs. J has been so kind to them—this could be another way of “paying,”