You cannot 'grow' a widow's peak. A widow's peak is genetic, and is determined by your genes, not by any other factors. It is permanent whether you have a widow's peak or not.

A widow's peak is a dominant trait, so even if a person has both the widow's peak and the straight hairline trait, only the widow's peak will be visibly apparent.

Widow's peak is a V-shaped point in the middle of the hairline (above the forehead) ((:

'Widow's peak' comes from the English folklore and it's meaning is that the woman will outlive her husband. The widow's peak itself is just a dominant trait that is inherited but it does not have any real meaning.

50% of their children are expected to have a widow's peak. When a heterozygous male (Ww) with a widow's peak gene marries a female with a straight hairline (ww), their offspring have a 50% chance of inheriting the widow's peak gene from the father.