package Father;
use strict;
use warnings;
use 5.010;
sub new {
        my $class = shift;
        state $shared_data = {};
        my $self = {
                's' => $shared_data
        };
        bless $self, $class;
}
sub s { return $_[0]->{s} }
1;

##</code><code>##

package Daughter; # or Son
use strict;
use warnings;
use 5.010;
use parent qw(Father);
1;

##</code><code>##

use strict;
use warnings;

use lib '.';
use Daughter;
use Son;

my $d = Daughter->new();
my $s = Son->new();

$d->s()->{'news'} = 'bad';

print $s->s()->{'news'}."\n";

my $d2 = Daughter->new();
print $d->s()->{'news'}."\n";

$d2->s()->{'news'} = 'bad123';

print $s->s()->{'news'}."\n";
print $d->s()->{'news'}."\n";
print $d2->s()->{'news'}."\n";

# prints
bad
bad
bad123
bad123
bad123

##</code><code>##

my $shared_data = {};
my $father = Father->new($shared_data);
my $d = $father->new_daughter();
...