Hello all! this is my very first post and I'm in need of some help

I'm getting ready to enter the process of ordering my very first kilt (a SWK standard) but I'v run into an odd problem. I would very much like to have some connection to the tartan I choose but have very little information available. I know that my Mum is a Stewart and her grand father was a Scottish national until he moved to Perry Sound Ontario. Now not a single person in any area of my family is interested in genealogy, compounded by the fact that when I showed the Royal Stewart to my Mum she was adamant that this was not "our" tartan. So now I am plying the brains of XMTS in hopes of clarification.

Btw I'v been hanging around for a while and if Belsen ever sees this. I need to know where he got that Oi Polloi sporran

Anyway thanks in advance and I hope to be kilted among everyone very soon!