i bet this is really about money. 54 yr old auntie can't afford the expense of the trip if she'd have to pay for a caretaker too. Meanwhile younger sis, who prob could treat her to a vacation is off with her daughter. Old auntie's disgruntlement has nothing to do with the niece and makes her look like an immature petty shrew. which she probably isn't, just an exhausted caretaker. she has (a no doubt long history of) deep resentment toward her sister, whom she feels isn't offering her fair share of elder care, in the name of having parental duties. LW needs to take her attention off her sister and examine other avenues for caretaker relief.