Actual JSON

{
    "date": "2021-10-13T14:13:28Z",
    "cost": 12.34,
    "mealsByPerson": [
        {
            "Tom": {
                "meat": "bacon",
                "eggs": "scrambled",
                "side": "hashbrowns"
            }
        },
        {
            "Jack": {
                "meat": "sausage",
                "eggs": "over easy",
                "side": "pancakes"
            }
        }
    ]
}

Expected JSON

{
    "date": "2021-10-13T14:09:32Z",
    "cost": 12.34,
    "mealsByPerson": {
        "Tom": {
            "meat": "bacon",
            "eggs": "scrambled",
            "side": "hashbrowns"
        },
        "Jack": {
            "meat": "sausage",
            "eggs": "over easy",
            "side": "pancakes"
        }
    },
    "mealsByPersonSize": 2
}