Frankly I didn't know what she was talking about and had to look it up to see if it was something to eat or wear. Apparently this is a big business in Scotland because there are a number of web pages you can use to look up your Tartan. I guess there are then any number of places to buy some of it on a roll or made into clothing.
With a name like Glenn you would assume the family came from Scotland. I looked back at the last known ancestor in the family and only have references to him coming from Ireland.
David Glenn 1745-1784 is found in many sources but they all say he came to the Colonies in the 1770s from Ireland. He settled in Newberry, South Carolina and served briefly during the Revolutionary War. He was given the rank of Colonel, and I'm not sure how. The Annals of Newberry, published in 1892 has a long account of his life and death.
I don't know much about the Scot - Irish history so it is possible the family had lived in Scotland before and moved to Ireland. Maybe some of you can explain it.