Is it possible the appearance of blue-eyed children if both parents have brown eyes?

Blue eye color is a recessive trait and only appears when homozygous. Let A be the gene for brown eyes, then a is the gene for blue eyes. Brown-eyed parents can have a blue-eyed baby, provided both parents are heterozygous.

RR g Aa (k) x m Aa (k)

g A.a A.a

F AA (k), Aa (k), Aa (k), aa (g)

The probability of having a blue-eyed child in a family where the parents are brown-eyed heterozygotes is 25%.