I've been playing around with the lining.  The fabric I'm going to be using is patterned, so I'm going to need a cream outer layer and the patterned inner layer.  I don't want the patterns showing through in between the flowers.  For messing around, I've made a test lining from a crappy old sheet that I keep around just for this purpose.

I cut the lining so it's the size of the purse when it was a flat rectangle.  Yes, amazingly, I thought to measure it before I sewed up the purse. ;)  So that my test is as close to the real thing as possible, I sewed two pieces of blue sheet together, turned them, ironed the edges, and sewed a one-forth-inch seam around the outer edge.

My first idea, which I don't have pictures of, was to gather the edges.  Oh, man, that was a crap idea.  How in the world would I sew all that fabric to the handles?  My second idea, which I also didn't photograph, was to do a series of elaborate pleats along each of the four edges.  Personally, I think that's the best way to go for an even pouf, but since my lining is two-thick ... four-thick on the turned edges ... this was going to get too thick for my sewing machine.  Plus, it was going to be a huge headache to figure out exactly how to do the pleats so the edges ended up the right width for sewing into the purse.

I don't mind taking the time to do the elaborate pleats, but I imagined there was an easier way, so I decided to strip the process down to it's simplest bits.

I measured the opening.  The front and back are 9.5 inches and the sides are 8 inches across.

Then I measured in half that distance from each corner on the sides of the lining.

Then I folded up the fabric in the middle, accordion-style.  The flaps on the right and left equal 9.5 inches and would be sewn into the purse.  The folded bits would be hidden between the lining and the crocheted flowers.

This is the lining with all four sizes accordioned up.

Here's what it looks like pinned into the purse.  I didn't like how the lining between the folds is pretty tight.  It wasn't terrible, but it still constricted the opening a little.

Next I tried putting all the pleats in the corners instead of the middle of each side.  I completely took out the previous pleats and folded up all the fabric on the corners leaving a 9.5 or 8 inch flat bit in the center of each side (no picture outside of the purse ... sorry).  I thought this would be better because I'd have a flat edge to attach to the purse instead of the two half-edges.  But this actually worked out worse.  First, the sides of the purse are curved, so the flat edge doesn't ease along the edge.  Second, pleating in the corners was more bulky and unwieldy.

In my next effort, I decided to split the difference.  I put two pleats on each side (spaced so that half the width is in the center and a forth of the width is on either side of that ).  This spreads out the bulk of the pleats and breaks up the line of the lining edge so it can curve around the opening.

Compare this photo with the other two open-purse photos above.  See how much open the opening seems?  Going from one to two pleats makes a huge difference.

So the lining is 90% planned.  I may still end up doing more pleats or adding a pocket.  Maybe not.  The important thing is that I know I can turn the big rectangle of fabric into a purse lining. I'll probably wait until next weekend to cut the lining out of the real fabric just in case I get a better idea for doing the pleats.