Woodbridge second row Louise Rickard, Bath prop Caryl Thomas, Dolgellau centre Elen Evans and Loughborough full-back Elinor Snowsill have been confirmed in what Lewis describes as a Welsh side which will enter the World Cup as underdogs in a tough group boasting world champions New Zealand, 7s champions Australia and South Africa.
"We named 23 to start with but it was always going to be the fact that there were 23 at that point of time who earned the right to go. But the squad knew if people weren't performing there was always the opportunity to change players and put others in.
"Now's the time where we've got to pick 26 and one player hasn't quite made the progress due to injury, as a result we've left her out of the squad and four others will now come into the squad of 22 to make the final squad of 26," explained Lewis.
Rickard was delighted to earn her call-up for her fourth World Cup. The ageless Rickard has moved from wing to second row and admitted the news took her by surprise.
"It was a total shock when Jason rang to let me know. I wasn't expecting the squad to be finalised until a couple of more weeks so it came out of the blue. I didn't really know if I would make it - the other times I suppose you take it for granted that you are going to be in the team but when you are right on the edge it means that much more to you."
Lewis added: "I'm really happy with the squad which we've got. I know it is a cliché but it is a real mixture of youth and experience. I think some of the young players who have come in have added some vibrancy and mixed things up a little bit. They've certainly shown they deserve their place here and I think there is a good spirit in the squad.
"Going into the World Cup, we're underdogs. If you go on line or read any press releases, Wales is always mentioned as the last name in the pool.
"I think people are writing us off in favour of the bigger names. Australia - World Cup winners at 7s, South Africa - because of what their male counterparts do and world champions New Zealand - they are fantastic. So nobody gives us a second thought, that's great, that suits us down to the ground, and that's a good place to be."
The World Cup will be staged at Surrey Sports Park and the Twickenham Stoop between August 20-September 5 with Wales kicking their campaign off against Australia on the opening day of the tournament.
Wales Women's World Cup squad (confirmed):
Forwards: Jenny Davies, Lowri Harries, Catrin Edwards, Rhian Bowden, Gemma Hallett, Shona Powell-Hughes, Louise Rickard, Rachel Taylor, Catrina Nicholas, Jamie Kift (captain), Sioned Harries, Lisa Newton, Caryl Thomas
Backs: Amy Day, Laura Prosser, Awen Thomas, Naomi Thomas, Mared Evans, Clare Flowers, Ceri Redman, Mellissa Berry (capt), Caryl James, Non Evans, Elinor Snowsill, Elen Evans.