Need suggestions for a bag

[Sinjah]

So, I'm crocheting my friend a bag for her birthday. It's made up of four granny squares on each side:



Each big square is about 12x12 inches. Now, originally, I was planning on just joining three sides of the squares together and adding straps, but then I started wondering that maybe the bag will end up being too small? Should I crochet a long strip to function as the sides and bottom? Should I just crochet for a couple rounds around the entire square to make it bigger? Should I go with my original plan?

Here's another picture with my hand for size comparison:

[IdlersDesign]

Looks pretty, that will be a lovely gift!
Maybe you could indeed make a long strip that will be bottom/sides/strap?

[sheepBlue]

Just an idea but I did a similar pattern that required a few more squares that turned out super roomy; here's the link

http://vallieskids.blogspot.com/2009/08/diamond-granny-bag.html

Here's the project I made with that pattern

[Cow Whisperer]

I would go with the strip for the sides and bottom. Maybe consider a piece of plastic canvas in the bottom for a bit of stability. You do really lovely, precise work. Your friend should be really happy, I know I would be!