Ayyy at 13 months, honestly the best thing is just to make sure dia makan well with protein, calcium, and fruits, a few of us tried giving more eggs, yogurt, and leafy greens, and we noticed a difference over time lah. Growth is so individual at this age, so I'd really suggest checking with the pediatrician to make sure there's no underlying issue, because sometimes kids just need a bit of time to catch up, sometimes ada other factors je!