New to rails, not sure how to model this

Check out acts_as_tree. It may be able to help you b/c it enables you
to model hierarchies.

In person.rb you would have:

class Person < ActiveRecord::Base
acts_as_tree :order=>"age" <-- or however you want to sort it

Make sure that in your schema you have a field called parent_id.
Somethin like:
create table people (
    id int not null auto_increment,
    parent_id int ,
    name varchar(200) not null,
    created_on datetime not null,
    updated_on datetime not null,
    constraint fk_person_parent foreign key (parent_id) references
    primary key (id)

When searching you can use an idiom I don't quite remember to pull up
all the children as well.