Flutterでのレイアウト

ボタンが含まれるColumnを右へ画面の端まで最大化する方法がわかりません。

Dart
1class MyApp extends StatelessWidget {
2  bool show = true;
3
4  @override
5  Widget build(BuildContext context) {
6    return MaterialApp(
7      home: Scaffold(
8        backgroundColor: Colors.white,
9        body: SafeArea(
10          child: SingleChildScrollView(
11            child: Content(show: show),
12          ),
13        ),
14      ),
15    );
16  }
17}
18
19class Content extends StatelessWidget {
20  const Content({
21    Key key,
22    @required this.show,
23  }) : super(key: key);
24
25  final bool show;
26
27  @override
28  Widget build(BuildContext context) {
29    return Column(
30      children: <Widget>[MessageContainer()],
31    );
32  }
33}
34
35class MessageContainer extends StatelessWidget {
36  const MessageContainer({
37    Key key,
38  }) : super(key: key);
39
40  @override
41  Widget build(BuildContext context) {
42    return Container(
43      height: 150,
44      child: Row(
45        children: [
46          Image(
47            width: 100,
48            height: 100,
49            image: NetworkImage(
50                "https://images.unsplash.com/photo-1590129617851-2eff07ed4d54?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=934&q=80"),
51          ),
52          Column(
53            crossAxisAlignment: CrossAxisAlignment.center,
54            children: <Widget>[
55              Text("text1"),
56              Text("text2"),
57              RaisedButton(
58                child: Text("button"),
59                color: Colors.green,
60                onPressed: () {},
61              )
62            ],
63          ),
64        ],
65      ),
66    );
67  }
68}
69