Children spend waaaay more time around parents and relatives.
Same reason why you are more likely to be killed by an intimate partner than a stranger. (This is not monocausal, and I do not mean to imply that simply spending time with someone will cause a crime)
It really depends on the exact framing of the question.
Are children safer ALONE with a random stranger or with a family member? Why is the child alone with a random stranger?
There are some broad daylight kidnappings, but they are relatively rare. They are relatively rare because it's much easier for a kidnapper to abscond with someone who trusts them.
https://xkcd.com/1138/
https://en.wikipedia.org/wiki/Base_rate_fallacy
https://en.wikipedia.org/wiki/Ecological_fallacy
Children spend waaaay more time around parents and relatives.
Same reason why you are more likely to be killed by an intimate partner than a stranger. (This is not monocausal, and I do not mean to imply that simply spending time with someone will cause a crime)