You got it right. If she likes it, it is a great idea. The fact that you like it too is even better. Unlike her wedding outfit, which probably will cost a lot and never be worn again, yours will be infinitely reusable. Go ahead, put some of that wedding budget into a nice sporran and maybe some patterned socks- I still think black socks with a kilt look like you forgot to put your trousers on.

And ABSOLUTELY, remember it is a big day, but it is only a day- the good part comes afterwards.