Set the space between Elements in Row Flutter

Code:

new Container(
          alignment: FractionalOffset.center,
          child: new Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: <Widget>[
              new FlatButton(
                child: new Text('Don\'t have an account?', style: new TextStyle(color: Color(0xFF2E3233))),
              ),
              new FlatButton(
                child: new Text('Register.', style: new TextStyle(color: Color(0xFF84A2AF), fontWeight: FontWeight.bold),),
                onPressed: moveToRegister,
              )
            ],
          ),
        ),  

And here is the result: https://dartpad.dev/?id=6bbfc6139bdf32aa7b47eebcdf9623ba

How to fix that the two FlatButton elements are side by side without space between the center of the screen width?

Removing Space-:

new Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              GestureDetector(
                child: new Text('Don\'t have an account?',
                    style: new TextStyle(color: Color(0xFF2E3233))),
                onTap: () {},
              ),
              GestureDetector(
                onTap: (){},
                  child: new Text(
                'Register.',
                style: new TextStyle(
                    color: Color(0xFF84A2AF), fontWeight: FontWeight.bold),
              ))
            ],
          ),

OR

GestureDetector(
            onTap: (){},
            child: new Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                new Text('Don\'t have an account?',
                    style: new TextStyle(color: Color(0xFF2E3233))),
                new Text(
                  'Register.',
                  style: new TextStyle(
                  color: Color(0xFF84A2AF), fontWeight: FontWeight.bold),
                )
              ],
            ),
          ),