Go to Utube and search "Sharon Schambers Stretching a Block" very clear and it works. She also shows how to shrink a block. These tutorials will help you solve any descrepencies in block sizing.

Don't give up!! Just enjoy the process, and all things can be adjusted when all the blocks are done. Perhaps your neighbor can help you at that point

When I was trying to sew together a lot of swap blocks I had this very problem. I cut freezer paper the exact size the unfinished squares should be. I ironed the paper to the back of the block. I could then line up the paper instead of the block edge to sew. If the blocks were off by more then 1/4" then I took it apart and re sewed it. If it was cut to small I used the block in the backing.

I would give them all a good press with Mary Ellen's Best Press. Sometimes, the problem isn't in the seams, but in the pressing.

No, don't give up. If you are just 1/4 off, I would say you are almost perfect. Just read these ladies helps and you'll do just fine. It is so much fun on here, I don't get much quilting done. I read and read.

This could work really well if you use sashing and alternate block. I did a quilt set on the diagonal with sashing and alternate blocks, and it worked very well. The blocks appear to be floating. Keep going with it and don't fret about blocks already done.

I have done this often. No one knows the original intent. As long as the colors or patterns are incorporated in the quilt elsewhere, no one would notice.

As long as these blocks are for yourself -

Do like the other responders said - finish the series and then worry about what to do next.

There are a lot of ways to 'make it work' - that aren't always shown on the pattern!

I have one quilt that I started and it was a really hard quilt...It really was turning me off from quilting...I stopped going to the class and I packed away the unfinished top..I will finish one day...I then started doing easier quilts and loved it..I have slowly been doing harder and harder ones..you may just need to put that one in the closet for a few years.

Sharon Schamber has some great videos on Youtube that show how to block a square to the correct size. If you search on her name there, you will find them (mixed in with a lot of other great Youtube videos she has there!).