Welcome to the Quilting Board!

Let them look thru some quilt books to see what attracts them & pick a few patterns. That way the quilt will be a surprise if it is a gift for them. Take them to store (orhave them look at a fabric website) to look at fabrics to give you an idea what what they like or let them pick the fabrics. This way you know they will be happy with what you make for them.
Choose severrtal patterns and then show therm pictures. I'm thinking Irish Chain.
Patchwork... thats definately old fashioned.
Maybe shabby chic???? My dd loves that look, with eyelets, pastel/faded fabric, lots of cotton and linen, etc. Just a thought.
Be safe. Ask them exactly what they mean.
This seems to be the bottom line. Ask them.. My daughter 37 thinks vintage is the 50's , the 60's is hippie, the 70's disco and the 80's big hair. LOL For me 1950's and before is vintage , when we hit the 1920's that's hitting the antique mark. The 60's is my childhood. lol
Make a string quilt with 30's, 40's reproduction fabrics. That ought to be vintage enough! froggyintexas
I would think that vintage may just mean something from the 1800's to very early 1900's - Civil War, Williamsburg look, or Victorian Era. Getting their ideas is the safest way to go. The cost in time and materials is way too high to create something they will not value.
The quilt you see, is a part of me.
In your hand is the sum of my parts
My mind, my body and a piece of my heart.
Wrap in it, lay on it, cry, and dream.
It's made to help you know what love means.