Hi,
You can make concoction of basil leaves and one clove Boil them in 1 glass of water and let it boil till 1/4th of if is left. After it cools down a bit, add one spoon of honey. Now, you can give your babies this, say, one spoon in the entire day.
Since babies are just 13 weeks old, I would suggest please consult doctor first. Though this concoction won't do ant harm but because doctors advice to give nothing except breastfeeding milk to babies below 6 months, so it is best to have a second opinion.
Joyce Joel