Flutter responsive framework - gap between ResponsiveRowColumnItem entries?

Question

I'm building a responsive Flutter form using the 'responsive_framework' package.

When setting up the form I want to use 'ResponsiveRowColumn' widget to control the form layout, with a number of 'ResponsiveRowColumnItem' entries.

However, I want to insert a gap between each ResponsiveRowColumnItem entry, a horizontal gap if the layout is row based, a vertical gap if its a column layout. Any suggestions on what to use to implement this gap?

Currently, I'm using the following as the gap...

  ResponsiveRowColumnItem(
    rowFlex: 1,
    child: ResponsiveWrapper.of(context).isSmallerThan(TABLET)
        ? SizedBox(
            height: 20.0,
          )
        : SizedBox(
            width: 40,
          ),
  ),