There are a lot of good suggestions here already. I would check to see if she has photos of her home on Facebok, or ask about her alma mater or sorority.

I never knew of her. but, it looks a lot like things I do. I can't do subtle, it's just not in me or my sewing machine

I would just ask her. Or at the very least, ask her parents what color her living room is and what kinds of things she and her future husband like.

Exactly what I thought! My next thought was to ask her what she'd like, though.

I think Marand is right on the money. A couch quilt/good size throw would be perfect. Every magazine, HGTV show, etc. seems to reflect shades of gray and white. Sometimes navy blue is thrown in with the gray and white. Low volume neutrals you couldn't go wrong with for a young couple.

check her registry or ask the mother what colors are used in her wedding and what the dress looks like (for instance, is it very traditional? vintage? more modern?)that would give you a clue about her taste.

I had this same problem with my little sister, my family has always been huge into quilts because of our grandmother so when I asked her what she wanted, I feared the worst and got it - she wanted a Double Wedding Ring.

To be honest, I haven't started it yet, the design became bigger than me, she went with fall colors for her wedding and I was up to 24 different colors, not counting the background color, which I chose. I scrapped my original plan to do it and I'm now focusing on designing a Diamond Double Wedding Ring using only four colors. The weight of the world is off my shoulders.

I would think something timeless and classic would be good. Grandmother's Flower Garden would be good and actually looks quite romantic in neutral/flesh tone/subdued colors, Shar Jorgensen done a wonderful show on it years ago that allows you to machine piece it instead of hand piece it and right now, I'm working on a lap quilt that seems to be morphing into a queen-size quilt, you can find the show on YouTube, just look for Quilting from The Heartland.

A log cabin design would be super fast and super easy, as well and done in the wedding colors would look fantastic, I've always loved those designs. I would suggest to just find a pattern that you enjoy, then add the wedding colors, which tend to lean towards the couple's favorite colors anyway.

You are getting so many suggestions here. Personally, I would do something quick and simple in the neutral colors and throw size. Even if you look at her wedding colors or those of her home, that will change over the years. Too, you don't know how well she will treat the piece so I wouldn't invest a lot of time. A rail fence can be quite interesting--not really modern nor traditional and works up quickly. What colors do you have in your stash that you'd like to use up but would be pleasing to anyone's taste? I recently did a chevron (half square triangles) that went quickly but chevrons are a bit on the trendy side that may not look as good in another 5 years. Rail fence is an "oldie but goodie".

Make her a throw for a season (Christmas, Fall, Valentine you get the idea). This will be a wonderful memory a long time.

You might ask your brother-in-law about his daughter's favorite colors to start with. If this individual gives you incomplete answers, ask the gal's mother. But above all I would suggest something that you would like.

I have been reading some of the comments from others and I like the idea of just simply asking the bride for what color grabs her heart. Then you can dive in with any pattern old, new, modern or traditional that brings you pleasure in creating with that color and coordinates.

I personally like the quilt from himnherr. It is a traditional pattern but being off set makes it modern and it is easy to make. Take her favorite color and run for your stash!