They then went on to collect the Grand Slam with a battling 6-3 win over Italy in Milan, played in torrential conditions.
They then returned home to a hero's welcome at Dublin Airport, where Coghlan praised the efforts of the whole squad.
"I don't think it has fully hit me what we have actually achieved," she told Irish Rugby TV.
"I think it was hard work. The work ethic of the girls, their commitment to everything we do - you ask them to do something and they do it. They are brilliant, absolutely brilliant.
"It was absolutely brilliant and I'm over the moon.
"If this can get more people involved and if this can drive the game on to a new level it is going to have women's rugby in a great place - and that is where we need it to be."