Nicholas-McLaughlin, who was capped 60-times for Wales, will continue as Gwalia Lightning head coach, while Beck, who won seven Wales caps, is head coach of Brython Thunder.
The WRU-owned franchises will compete in the new expanded home and away Celtic Challenge tournament, between teams from Wales, Ireland and Scotland.
The cross-border tournament is in its third season with Gwalia Lightning and Brython Thunder representing Wales against Scottish clubs, Edinburgh and Glasgow, and Irish teams, Clover and Wolfhounds.
The home and away Celtic Challenge will kick-off at the end of December and runs until March and every team will play each other on a home and away basis.
Nicholas-McLaughlin, who was head coach of Wales Women’s U18s and assistant coach for Wales Women’s U20s, led a young Gwalia Lightning squad last season and saw the likes of scrum-half Sian Jones, Number 8 Gwennan Hopkins, wing Catherin Richards, hooker Molly Reardon, prop Maisie Davies and lock Alaw Pyrs, all make their full Wales debuts.
Nicholas-McLaughlin, said: “The Celtic Challenge proved a fantastic experience for our young squad, and they used it to further their development as players.
“The likes of Nel Metcalfe, Gwennan Hopkins, Sian Jones and Molly Reardon used it as a real launchpad for recognition as a higher level and established them in the Wales senior squad and after the tournament went on to play for their clubs in England.
“We established our team and playing identity during the campaign and having experienced internationals like Bryonie King and Kate Williams in the squad gave some real experience for the younger players to lean on.”
Beck, who has been appointed Wales WU20s Attack coach and played more than 100 games for the Ospreys, led an experienced Thunder squad with the Wales Test stars, likes of Alex Callender, Natalia John and the now retired Sioned Harries, last season.
Beck, said: “Working with established international players was a really enjoyable experience and to see how invested they were in the squad underlined how important the Celtic Challenge is as a tournament.
“We grew into the competition as a squad and, if we are honest, the tournament probably finished just as we were getting started as team and establishing our playing combinations and style of play.
“The opportunity to play home and away in the Celtic Challenge is a real challenge but one I know all the players will relish. The chance to test yourself against the best in Wales, Ireland and Scotland is mouthwatering prospect.”
Gwalia Lightning finished third in the final Celtic Challenge table and both teams won a game each in two pulsating Welsh derbies at Rodney Parade and Parc Y Scarlets.
