How to place tree node not to overlap with tikzpicture?

Question

I'm trying to draw a tree diagram using tikzpicture, the issue is that when the distance between nodes are not wide enough the tree nodes are wrapping. As I use two column style, I need to find a way not to overlap the nodes. What might be the options?

\documentclass[border=10pt]{standalone} 
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[sibling distance=5em,
    every node/.style = {shape=rectangle, rounded corners,
        draw, align=center,
        top color=white, bottom color=white}]]
    \node {\textit{$sentence_i$}}
        child { 
        { node {Sender} 
            child { node {Name} }
            child 
            { node {Location} 
                child { node {Latitude}}
                child { node {Longitude}}
            }
        }}
        child    { node {Event}}  
        child    { node {Datetime}
            {
                child { node {Date}}
                child { node {Time}}
            }
        }      
        child    { node {Location'}
            {
                child { node {Lattitude'}}
                child { node {Longitude'}}
            }
        };
\end{tikzpicture}
\end{document}