How to make the first row and second row in the center to with respect to each other in Flutter?

Code :-

Widget showAttachmentsInBottomSheet() {
return SizedBox(
height: 270,
child: Card(
  child: Column(
    mainAxisAlignment: MainAxisAlignment.center,
    children: [
      Row(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: const [
              CircleAvatar(
                radius: 24,
                backgroundColor: Colors.blue,
                child: Icon(
                  Icons.file_present,
                ),
              ),
              Padding(
                padding: EdgeInsets.all(8),
                child: Text(
                  "Attachment",
                  style: TextStyle(fontSize: 14),
                ),
              )
            ],
          ),
          const SizedBox(
            width: 40,
          ),
          Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: const [
              CircleAvatar(
                radius: 24,
                backgroundColor: Colors.red,
                child: Icon(
                  Icons.camera,
                ),
              ),
              Padding(
                padding: EdgeInsets.all(8),
                child: Text(
                  "Camera",
                  style: TextStyle(fontSize: 14),
                ),
              )
            ],
          ),
          const SizedBox(
            width: 40,
          ),
          Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: const [
              CircleAvatar(
                radius: 24,
                backgroundColor: Colors.purple,
                child: Icon(Icons.image),
              ),
              Padding(
                padding: EdgeInsets.all(8),
                child: Text(
                  "Gallery",
                  style: TextStyle(fontSize: 14),
                ),
              )
            ],
          )
        ],
      ),
      const SizedBox(
        width: 40,
      ),
      Row(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: const [
              CircleAvatar(
                radius: 24,
                backgroundColor: Colors.orange,
                child: Icon(
                  Icons.music_note,
                ),
              ),
              Padding(
                padding: EdgeInsets.all(8),
                child: Text(
                  "Audio",
                  style: TextStyle(fontSize: 14),
                ),
              )
            ],
          ),
          const SizedBox(
            width: 40,
          ),
          Column(
          
            mainAxisAlignment: MainAxisAlignment.center,
            children: const [
              CircleAvatar(
                radius: 24,
                backgroundColor: Colors.green,
                child: Icon(
                  Icons.location_pin,
                ),
              ),
              Padding(
                padding: EdgeInsets.all(8),
                child: Text(
                  "Location",
                  style: TextStyle(fontSize: 14),
                ),
              )
            ],
          ),
          const SizedBox(
            width: 40,
          ),
          Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: const [
              CircleAvatar(
                radius: 24,
                backgroundColor: Colors.pinkAccent,
                child: Icon(
                  Icons.contact_phone,
                ),
              ),
              Padding(
                padding: EdgeInsets.all(8),
                child: Text(
                  "Contact",
                  style: TextStyle(fontSize: 14),
                ),
              )
            ],
          )
        ],
      )
    ],
  ),
  shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(6)),
),

); }