The Scots have not won a match in the event since 2010, but the performance of the current crop of players against Ireland in this year’s opener earlier in the month was impressive.
They went down 22-15 in the end and took great heart from that showing.
That same weekend, Wales laboured to a 20-8 away win in Italy while both sides lost heavily last time out, Scotland 55-0 in France and the Welsh 63-0 at home to England.
Centre Martin said: “Everyone was really buzzing to get back into camp this week after a few days off.
“We have trained well and it is about finding the extra edge to take into games that could see us over the line to a win.
“Ireland was a massive game for us, on the face of it we lost the game, but for us to be in it for 80 minutes I think has really given the girls a bit more inner belief that we can compete with these sides.
“The France match was tough, they just got their offloading game going and some of our girls had not played in front of such a big crowd before.
“However, the pleasing thing for me is that nobody went into their shells after it and there was no blaming each other.
“We have stuck together and come up with a game plan that we think can trouble the Welsh.
“They have some good players, but we are at home and like the Irish match we have to get off to a good start and really build from there.”
Jemma Forsyth comes into the Scotland starting XV in the back-row in the only change from the France match.
Karen Dunbar is injured and will miss the rest of the championship.
For Wales, Team GB Olympic sevens squad member Jasmine Joyce and scrum-half Rhiannon Parker come in for debuts.
Joyce is on the wing and in Wales’ recent uncapped game against Spain she scored two tries from the bench.
Wales head coach Rowland Phillips said: “The girls who have come in have made a big impression in training and they deserve their chance.”