Alter only one branch properties

Question

I have a diagram in tikz-qtree like figure A, but I'd like something like figure B. Is it possibe, to alter the properties of only one brach? (these figures made with Dia and arrows not important)

edit: (added my modified code, based on Alan Munn's answer)

\begin{center}
\begin{tikzpicture}[grow'=right,level distance=1.45in,sibling distance=.2in]

\tikzset{edge from parent/.style= 
{thick, draw, edge from parent fork right},
  every tree node/.style=
    {draw,minimum width=1.3in,text width=1.15in,align=center}
}
\Tree 
  [.parent
    [.child0
      grandchild0-0
      grandchild0-1
      [[.{grandchild0-2} 
        {greatgrandchild0} 
        {greatgrandchild0}
        {greatgrandchild0} 
        {greatgrandchild0}
      ]] 
      grandchild0-3
    ] 
    [.child1
      [.grandchild1-0 ] 
      [.grandchild1-1 ] 
    ] 
  ]
\end{tikzpicture}
\end{center}

Answer 1

You can add extra brackets around a node to extend its branch:

\documentclass{article}
\usepackage{tikz}
\usepackage{tikz-qtree}
\usetikzlibrary{trees} % this is to allow the fork right path

\begin{document}

\begin{tikzpicture}[level distance=1.25in,sibling distance=.15in,scale=.75]
\tikzset{edge from parent/.style= 
            {thick, draw,
                edge from parent fork right},every tree node/.style={draw,minimum width=1in,text width=1in, align=center},grow'=right}
\Tree 
    [. parent 
        [.{nice child0}
                [.{grandchild0-0 } ]
            [.{grandchild0-1 } ]
            [.{grandchild0-2 } ]
            [.{grandchild0-3 } ]
        ]
        [[[.child1
            [.{grandchild1-0 } ]
            [.{grandchild1-1 } ]
            [.{grandchild1-2 } ]
        ]]]
        [.child2 ]
        [.child3 ]
    ]
\end{tikzpicture}
\end{document}

Answer 2

I managed to find a solution to my problem without qtree baesd on this one: How to modify the distance between branches when drawing trees using TiKZ?
The code:

\documentclass[a4paper,12pt]{article}
\usepackage{tikz}
\usetikzlibrary{trees}%szögletességhöz kell
\begin{document}

\begin{tikzpicture}[grow'=right,level distance=90pt,sibling distance=30pt]

\tikzset{edge from parent/.style= 
{thick, draw, edge from parent fork right}
}

    \node [draw] (z){parent}
        child { 
            node[draw] (a) {child0}
            child { 
                node[draw] (c) {grandchild0-0} 
            }
            child { 
                node[draw] (d) {grandchild0-1} 
            }   
            child { 
                node[draw] (e) {grandchild0-2} 
            }   
            child { 
                node[draw] (f) {grandchild0-3} 
            }   
        }
        child {
            node[draw] (b) {child1}
        }
        child {
            node[draw] (b) {child2}
        }
        child {
            node[draw] (b) {child3}
            child { 
                node[draw] (c) {grandchild3-0} 
            }
            child { 
                node[draw] (c) {grandchild3-1} 
            }
        }
        ;

    \path (z) -- (a);
    \path (z) -- (b);
    \path (a) -- (c);
    \end{tikzpicture}

\end{document}