Finding and Replacing Strings

[blackspyder01]

I kinda have a problem. What i'm tryin to do is read a couple or lines or so from a text file and then replace all the gender pronouns ie(he, she, him, her) and replace those with gender neutral ones. The problem i'm having is trying to find all the gender pronouns and replacing them Her is a example of my code so far. Any help would be a God send.

#include<iostream>
#include<string>
#include<fstream>


using namespace std;

   int main()
   {
       ifstream gender;
        gender.open("Proj1.txt");
         string str1="", str2=" he", str3=" she", str4=" him", str5=" her",str;
     int  pos =0;
     if (gender.is_open())
     { 


        while(!gender.eof())     
        {
            getline(gender, str1);
            pos=str1.find(str2,0);
                  cout<<str1.replace(pos, 3, " he or she"<<endl;

                    getline(gender, str1);
        }
     }


            gender.close();


       return 0;

   }