Hello Pauline,

The age for marriage was much younger than 21 years of age.

Extract from, A Manx Notebook,

At the bottom of the web page.

Legal Age

The 1673 will of Will Sayle [headed both Andreas and Jurby] records that he died "about the 4th Feb 1673" and ordained his "Ant Issabb Cleator als Clark" exec. until his two sisters Ales and Bahee Sayle became of lawful years.
This document followed: "Feb 13th 1674 ---finds that the testator was at lawfull years, for by certified out of the Church Register, it appears he was born Apll the 6th 1659. And being buryd the sixth of Feb 1673 by computate his age at his death was 14 years & 8 months, see that the Court proceedings were Legall in this particular...

Thus 14 was also the lawful age to leave a will as also to get married

ht tp://www.isle-of-man.com/manxnotebook/famhist/genealgy/wills.htm
(close gap ht tp)

Averil