One way could be to extract the childrens ages into an array using map before printing them. Perhaps also consider printf to format the output.

#!/usr/bin/perl

use warnings;
use strict;

my %alex = (
  age => 30,
  children => [
    {age => 2},
    {age => 5},
  ],
);

my @kids = map{$_->{age}} @{$alex{children}};

print   "Alex children are
        $kids[0] 
and     $kids[1] years old\n";
print   "Alex is $alex{age} himself\n\n";

# or

printf(
  qq{Alex's children are %d and %d years old\nAlex is %d himself\n},
  @kids, $alex{age}
);
[download]