Thank you so much Barbara. I'll give this a shot. I'm also starting this year's BOM but am hoping to keep up!
bbquiltmaker wrote:

Julie, don’t panic. First, use a small ruler to check the pinwheels in the short border. My pattern is put away but I think they were 3” finished. Start at one end and measure each one—3” from seam to seam. You will find the ones that are “short”—take the seam apart on the short ones and re-sew. I think you will find those missing inches in the seams.

Going forward, it really helps to check yourself as you go. Sew pinwheels in pairs, check they are correct. Sew pairs to pairs, check the size. You want to find the problem as soon as it happens, not after you have the whole border sewn.

Barbara - OMG please help if you can. I'm finally (yes, I'm slow) on month 8 and I have a huge (but very tiny) floater issue. My quilt center measures 55.5" just as it should, but my short pinwheel boarder measures 55.75" - almost 2" smaller than it should. I know this is some kind of seam problem but here I am with all those pinwheels sewn and I just can't bring myself to start all over with them (not to mention I may not have enough fabric!) This predicament tells me I'll need to do .25" floaters but with all those points to get perfect on the half square triangles from month 6, plus the pinwheels I'm really worried this is going to look terrible. My long pinwheel strips measure 61". Do you have any suggestions? If I used background fabric for the floater any minor variations on the seams wouldn't be as visible but I'm not sure the look would be ok. Any thoughts would be GREATLY appreciated. I am a very experienced quilter and former shop owner - not sure how I got myself into this predicament!