Wales had the game in the bag by halftime with a comfortable 21-7 lead but could only add one further try in the second spell through replacement Mared Evans. Scotland scored a late consolation try through captain Lynne Reid.
Wales coach Jason Lewis was a delighted man after guiding his side to victory.
"This was a very pleasing win which has got us back on track. Scotland came here full of confidence having beaten France. They were up for it but to be fair the girls went out and worked to the game plan. They stuck to it and it paid dividends," he said.
Wales made all the early running with Mellissa Berry, moved into midfield from the back of a scrum because of a shoulder injury to Claire Flowers, proving a threat from the outset.
However it was a bullocking run from prop Catrin Edwards which set up Wales for their first try. She tore into the Scottish defence to tempt the visiting side into an offence. The normally reliable Non Evans missed the penalty but she quickly made amends when she chipped across field and James latched onto the ball to score in the corner.
Evans then rifled over the sideline conversion to give Wales a 7-0 lead. Scotland finally got the ball and worked their way towards the Welsh tryline. Fly half Tanya Griffith danced her way through the Welsh defence to score near the posts which scrum half Louise Dalgliesh improved to even the score.
The game was played at a frantic pace with Rachel Taylor, playing in the unaccustomed position of No 8, hitting the line like a steam train to deliver a delicate Ceri Redman pass to send the speeding James over for her second try in the 16th minute. Evans added the extras to give Wales a 14-7 lead.
Wales increased their lead in the 31st minute after a slashing break from scrum half Laura Prosser took the home side inside the Scottish 22. Awen Thomas, in her 50th appearance for her country, then pulled the Scottish defence sideways to give the flying Evans a sniff of a chance which she accepted with aplomb.
With a handy 21-7 lead at the break Wales seemed to be in control. However after the break they lost their momentum but were still not afraid to throw the ball around.
Evans made an instant impact when coming on as a late replacement for James. Evans has been frustrated with a lengthy injury list, but made her presence felt immediately when slicing through the Scottish defence like a hot knife through butter. Evans landed the conversion to give Wales a comfortable 28-7 lead.
Scotland finished brightly with Reid barging her way over near the corner flag but by then the result was already a formality.
Scorers: Wales: Tries: James (2), Non Evans, Mared Evans; Cons: Evans (4)
Scotland: Tries: Griffith, Reid; Con: Dalgliesh