@Mika Yes, the girl is not a professional babysitter, but she is the eldest in the family. Perhaps that's why my friend was comfortable with her taking care of the baby, as she might have taken care of her younger siblings. I am glad nothing serious had happened, though the baby was crying all the time and the girl had to carry the baby for hours. I don't even dare to leave my children at home alone without any adults, even my eldest is 9 years old. It's also against the law to leave a kid or kids at home without any adults. I am fine with my elder children playing with my baby without me or my husband being there after he was over 1 year old or older, but we still always go and check out how they are. Even though I know my elder children can take good care of the youngest brother, they are still kids. Perhaps I am just over protective. I'd better be this than feel sorry and regret later.