I didn't find Mad About Plaid, or Mad For Plaid but did find a couple other Plaids by Lyn Mann ....
http://quiltsbylyn.com/patterns1.htm
Her Plaid Madness looks like it would take a lot of fabric.
So yes, the large amount does look possible.
As mentioned already ... she may also be giving a good overage to allow for any "oops" moments.
Better to have too much, than to be fretting one is going to be short.
Welcome to the QB and Good Luck!