Why did Emma go away 2 weeks prior to the murders?

[kwest919]

I understand that there was and argument in the household that basically drove the girls away
But was it really that bad of an argument?
I mean.. from all that I've read about Emma.. which there really isn't much. She just doesn't seem like the type of person to say during those years.. I've had enough and I got to get out of here for awhile. Specially since she is basically portrayed as a homebody and someone who really never ventured out except to visit with friends within the town, Rev. Buck and his family and maybe the summer farm in Swansea. since her return from her time at school at Wheaton.
So why is it that she suddenly decides that she must go and spend 2 weeks or more in Fairhaven? She could have easily gone during the spring or earlier in the summer months. And why upon receiving the telegraph to come home didn't she get directly on the next train but wait for a later one?

Another thing. Lizzie. She goes to Marion to visit a school friends mother and sister. Which I can see... cause she was the more sociable of the two. But I read somewhere that when she left them.. she didn't go directly home. She stayed in a boarding house/ hotel for 4 days prior to returning to the house. Am I getting this right? Or was this a different time when she went away to visit other people? Either way.. why didn't she go directly home? Which establishment did she stay at? Where was it located and who was the proprietor? For Lizzie... I could see her doing this just to get away from everyone and have some free time alone. But again.. why at that point in time right before the murders?