Congratulations to your friend!
I have a friend who just found out she is having twins and is 13 weeks too!
I'm busily getting my stash together for my twins. I have added to my little boy's stash by getting some in swaps and have also been doing lots of sewing!!! I think I have probably gone a little over the top as I will have approx 30 NB fitteds, 26 infant prefolds, 12 NB covers, and 20 NB AIOs. Then in small 40 snappiable fitteds (an assortment of homemade terry towelling outers and Sherpies and Bambams from Bubblebubs), 15 normal fitteds, 8 covers and 20 AIOs. Then maybe a dozen OSFM fitteds half that Ollie still uses too. This is the first time I have worked it out and OMGosh I have a lot of nappies but at least I've used up a lot of the material I had been collecting over the past 2.5 years! LOL
I am expecting the girls to be on the smaller side which is why I have decided to go with lots of NBs aswell as smalls and it is only going to be early Spring in Melbourne so drying time may be in issue (and if they are anything like their brother they'll be pooing every feed, sometimes more than once). Being summer babies your friend might not have to worry about drying time as much.
I think the snappiable fitteds are going to be fantastic as they'll give a nice close fit and the rise can be folded down at the front to make it a little smaller if it's too big on the babies. If I didn't enjoy sewing so much I probably would have just made these to see me through the NB and smalls stage and not worried about having both sizes and gone with more prefolds but I can't help myself! hehe
Of course I haven't tried out the stash yet to know how good it is but I'm happy to let you know in about 10 weeks time when they arrive