Aggregate result in django rest framework

Question

In my posgresql I have a model "words":

class Words(models.Model):
    word = models.CharField(db_index=True, max_length=50)
    lesson = models.ForeignKey(Lesson, on_delete=models.CASCADE)
    time_stamp = models.TimeField(auto_now=False, auto_now_add=False)

In my view, after a query, I search for words that icontains the query itself A lot of words are duplicated and i need to aggregate them in the result My goal is to respond with a json file that collects the various words and lists their timestamps Something like this:

[
    {
        "word": "foo",
        "list": 
          [
            {
              "id": 10416,
              "lesson": 11,
              "time_stamp": "00:02:49.100000"
            },
            {
              "id": 10702,
              "lesson": 12,
              "time_stamp": "00:27:31.300000"
            },
            ...
          ]
    },
    {
        "word": "too",
        "list": 
          [
            {
              "id": 10416,
              "lesson": 11,
              "time_stamp": "00:02:49.100000"
            },
            {
              "id": 10702,
              "lesson": 12,
              "time_stamp": "00:27:31.300000"
            },
            ...
          ]
    },
]

I found two solution but both with downside

1- rework the database like this:

class WordsName(models.Model):
    word = models.CharField(unique=True, db_index=True, max_length=50)

class WordsDetail(models.Model):
    wordName = models.ForeignKey(WordsName, on_delete=models.CASCADE)
    lesson = models.ForeignKey(Lesson, on_delete=models.CASCADE)
    time_stamp = models.TimeField(auto_now=False, auto_now_add=False)

but it's a big change

2- make another Serializer:

class WordListSerializer(serializers.ModelSerializer):
    word = serializers.SerializerMethodField('get_word')
    list = serializers.SerializerMethodField('list_word')

    class Meta:
        model = Words
        fields = ['word', 'list']

    def get_word(self, obj):
        return obj.word + '*'

    def list_word(self, obj):
        word = Words.objects.filter(word=obj.word)
        return BinomiSerializer(word, many=True).data


class WordSerializer(serializers.ModelSerializer):
    class Meta:
        model = Words
        fields = ['id', 'lesson', 'time_stamp']

It works but i don't know if it is legal and it makes a lot of query to the db