Doesn't compile C++ Code

I am new to C++ and I am trying to create an object but somehow the compiler does not compile and throws me an exception "Exception thrown at 0x76EBE3DC (ntdll.dll) in projectLinkedList.exe: 0xC0000005: Access violation reading location 0x00829CE8." while popping up the "CreateProcessA.cpp". I have no idea on how to solve this issue. I think there are some errors in my code.

This is my code in .h

#ifndef WORDDATA_h
#define WORDDATA_h
#include "NumList.h"

class WordData
{
    private:
        char* wordData;
        int wordLength;
        int frequency;
        //declare a numlist object
        NumList numList;

        //print function
        friend std::ostream& operator<< (std::ostream&, const WordData&);

    public:
        //default constructor
        WordData();

        //parameterized constructor 
        WordData(std::string word, int linenumber);

        //destructor
        ~WordData();

        //copy constructor
        WordData(const WordData&);

        //copy assignment operator
        WordData& operator= (const WordData&);

        //setter
        void addFrequency();


        //getter
        int getNumListFElement() const;

        bool searchLineNum(int) const;
        void appendLineNum(int);
        int frequencyCount() const;

        //read-only pointer to the stored word
        const char * getPointerWordData() const;

        //read-only reference to the numlist object
        const NumList getReferenceNumList();

        //compare 2 words
        int compare(const WordData&) const;


};

#endif 

This is my code in .cpp

#include <iostream>
#include <string>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "WordData.h"

using namespace std;
//Default Constructor
WordData::WordData()
{
    wordData = nullptr;
    wordLength = 0;
    frequency = 0;
    NumList numList;
}

WordData::WordData(std::string word, int lineNumber)
{
    //Covert the string to lowercase
    for (size_t i = 0; i < word.length(); ++i) {
        if ('A' <= word[i] && word[i] <= 'Z') {
            word[i] = char(((int)word[i]) + 32);
        }
    }

    wordData = new char[word.length()+1];

    //Set a dumpy max char of 50
    strcpy_s(wordData, 50, word.c_str());
    wordLength = sizeof(wordData) / sizeof(*wordData);
    frequency = 1;
    NumList numList;
    this->numList.insertEnd(lineNumber);
}

//Destructor
WordData::~WordData()
{

}

//Copy Constructor
WordData::WordData(const WordData& anotherWord)
{
    wordLength = strlen(anotherWord.wordData);
    frequency = anotherWord.frequency;
    numList = anotherWord.numList;
    wordData = new char[wordLength+1]; //+1 for \0 at the end
    //for (int i = 0; i < wordLength; ++i)
    //{
    //  wordData[i] = anotherWord.wordData[i];
    //}
    strcpy_s(wordData, 50, anotherWord.wordData);

}

//Copy Assignment Operator
WordData& WordData::operator= (const WordData& anotherWord)
{
    //Calling copy constructor
    WordData temp(anotherWord);

    //Exchanging the content of WordData
    std::swap(wordData, temp.wordData);
    std::swap(wordLength, temp.wordLength);
    std::swap(frequency, temp.frequency);
    std::swap(numList, temp.numList);

    return *this;
}

//Setter
void WordData::addFrequency()
{
    frequency += 1;
}

//Getter
int WordData::getNumListFElement() const
{
    return numList.getElement(0);
}


bool WordData::searchLineNum(int lineNum) const
{
    if(this->numList.search(lineNum))
        return true;
    else
        return false;
}

void WordData::appendLineNum(int lineNum)
{
    if (!(this->numList.search(lineNum)))
        this->numList.insertEnd(lineNum);
    else
        cout << "The line number already exists in the list." << "\n";
}

int WordData::frequencyCount() const 
{
    return frequency;
}

//Read-only pointer to the wordData
const char* WordData::getPointerWordData() const
{
    return wordData;
}

//Read-only reference to the numList
 const NumList WordData::getReferenceNumList()
{
     NumList numList;
     return numList;
}

//Compare 2 words
int WordData::compare(const WordData& anotherWord) const
{
    return (strcmp(anotherWord.wordData, wordData));
}


std::ostream& operator<< (std::ostream& out, WordData& word)
{

    out << "The word of " << word.getPointerWordData() << " has a frequency of " << word.frequencyCount() << "\n" << "It appears on lines "; 
    word.getReferenceNumList().print();
    return out;
}

This is my code in main

#include <iostream>
#include <string>
#include "WordData.h"

int main()
{
    cout << "Hello" << endl;
    WordData data1("hello" , 10);
    data1.getPointerWordData();




    system("pause");
    return 0;

}