The sister-in-law is unreal!

Puh-lease! If Holly is as independent as she seems, why did she never tell the sister-in-law to get over it and mind her own business? I love the movie - really cute, though unbelieveable, storyline and Patrick Muldoon is the best part of the whole thing, but really.....she just looks at her brother's wife like she's indulging a small child. It's out of character for Holly, to say the least....