Is it permissible for a woman to uncover herself in front of a ten-year-old boy if he is not one of her mahram (relatives one may not marry)?

Question:
A boy who is ten years old, is it permissible for a woman to uncover herself in front of him if he is not one of her mahram (relatives one may not marry)?

Answer:
If a boy reaches puberty by the appearance of one of the signs of puberty, either by ejaculating semen with desire, or by growing coarse hair around the private parts, or by reaching the age of fifteen, these three signs are the markers of puberty; if any one of them occurs, he is an adult.