Wow! So many replies ... thank you all so very much! I feel much better now about pre-washing my fabrics. I have bought fabrics at this quilt shop once before, from this same line, and found them to hold up very, very well to washing. Honestly, I almost never work with reproduction fabrics because I don't have much use for them but the quality of the actual fabric is the best I've worked with (I usually love Robert Kaufman fabrics & use his line exclusively except for an occasional Moda Bella solid -- nothing wrong with other lines, it just helps me to match colors).
I thought it would be fun to work with 1930's reproduction fabrics since I'm making a single-Irish chain Sunbonnet Sue quilt. I normally wash & press all my fabrics as soon as I get home from the store. Maybe the lady just thought I would prefer saving the time of washing and pressing everything; I don't know. I'm just going to go ahead and wash everything and not worry about it. It's my time and my quilt and since it won't affect the final look of the quilt, I'm going to just do what makes me happy.