Annette,
I see what you mean. With items that are aligned (floated in CSS speak) to the left or right, they create a row of sorts and don’t fill in the space with the items below.
One way to have everything line up is to assign a minimum height. In you case, it might be good to apply that to your home page text widgets.
To use this, go to the theme options page and select the styling tab. Scroll down to the bottom until you see a box for custom CSS. Paste this into the box:
#home-widgets .widget.widget_text {
min-height: 150px;
}
and save your changes.
That will make your text widgets a minimum of 150 pixels tall. That should cause the first three to form a nice row across the top and the next three widgets to fit in below them.
If you end up changing the amount of text in your text widgets there, you may need to adjust the 150 to get the right fit.
Let me know if you have any questions or trouble.
Bill