Pegs was very important as a member of the tower group in my opinion. Well, not directly important - and I do not want to sound too harsh - but indirectly, she encouraged people by her behaviour not to judged as pejoratively as Pegs. It is really hard to explain, the world collapsed, zombies everywhere, however as long as you still have a better standing than others (i.e. Pegs), I think you at least think twice before you start to complain. Because you do not want to be the second Pegs. Hence, Pegs unintentionally played a vital role in season 1 - and to a certain degree - season 2.