Is this upbringing, which prevents a girl under the age of five from shaking hands with men, even unmarriageable kin (mahram), considered to be in accordance with the guidance of the Prophet, peace and blessings be upon him?

It is permissible for a man to shake hands with a girl who has not reached the age of five, as long as the handshake is without lust, due to the absence of fear of temptation. It is permissible to touch a young girl before the age of seven, unless she reaches the age of desire (shahwa), in which case touching her becomes forbidden. The prohibition of a young girl shaking hands should be postponed until she reaches the age of desire. Gentleness and wisdom should be employed in raising children.