Question:
Is it a problem of yichud for a 18 year old girl to babysit over-night for her 2 nephews: the first one is 12 years old, and the second one is 7 years old(no one else home)
Answer:
Yes. She would have to arrange something to block the yichud. Such as have someone that would seriously come in, just to check up on them in the middle of the night.
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