Set height of child elements equal to highest other element that are contained by Wrap Widget (Flutter)

What you need is InstrinsicHeight widget. Here is an example of how to solve your problem for any given number of cards in row. As you can see the _generateRows(List<String> labels, int numPerRow) function gets a collection of card labels and a number of cards in a row as input parameters and generates the layout:

  List<Widget> _generateRows(List<String> labels, int numPerRow) {
    Widget _buildTransferItem(String transferTitle, int numPerRow) {
      return Builder(
        builder: (context) {
          return Container(
            width: MediaQuery.of(context).size.width / numPerRow - 20,
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(12.0),
              boxShadow: [
                BoxShadow(
                  color: Color.fromRGBO(140, 140, 140, 0.5),
                  blurRadius: 6.0,
                )
              ],
            ),
            padding: EdgeInsets.symmetric(
              vertical: 20,
              horizontal: 20,
            ),
            child: Column(
              children: <Widget>[
                Icon(
                  Icons.info,
                  size: 48,
                ),
                SizedBox(height: 7),
                Text(
                  transferTitle,
                  style: TextStyle(
                    fontSize: 14,
                    fontWeight: FontWeight.w300,
                  ),
                  textAlign: TextAlign.center,
                )
              ],
            ),
          );
        },
      );
    }

    List<Widget> result = [];
    while (labels.length > 0) {
      List<String> tuple = labels.take(numPerRow).toList();
      for(int i = 0; i< tuple.length; i++){
        if (labels.length > 0) labels.removeAt(0);
      }
      Widget item = IntrinsicHeight(
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          children: tuple.map((s) => _buildTransferItem(s, numPerRow)).toList(),
        ),
      );
      result.add(item);
    }
    return result
        .expand((item) => [
              item,
              SizedBox(
                height: 20,
              ),
            ])
        .toList();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Transfers'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: _generateRows(
            ["Some text of this box", "Text", "Some Text of this box", "Some Rather Long Text of this box", "Cool, yeah?", "Last"],
            3,
          ),
        ),
      ),
    );
  }

The IntrinsicHeight widget takes into consideration intrinsic dimensions of the child which for most container widgets like Row, etc. will be definite numbers. But it comes with performance warranty of O(N^2) in complex cases as you may read in the API docs. Here are screenshots of cases when number of cards per row are 2 and 3. Please note that this parameter is passed just once and is not hardcoded anywhere.

If there's an odd number of items it will center last item:

The way you are applied width of Container using media Query. Same way you can apply for Height or you can write manual for example

height: 300.0,

And to match parent of Column you can write following code :

 Column(
mainAxisSize: MainAxisSize.max, // match parent
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <widget>[
  // your widget
]