It was a romance novel I read in early 2000s. This young girl lives with her sister and brother-in-law at first. The girls' mother gets sick and the older sister has to take care of her. The younger girl then has to go stay with her brother-in-law's older brother, who is wealthy. When she was younger, she liked the older brother because he was cool and let her do almost anything she wanted. When she goes to stay with him, at first it seems like she doesn't like him and argues with him a lot, but then they fall in love with each other. I remember one scene where he was out of town and she had this big party in his house but he comes home early and finds the place a mess.If anyone knows what I'm talking about, please help

Do you remember any names of people, towns, country it was in?