My twin nieces left for college this week and my heart goes out to my sister-in-law (SIL) who will face the empty nest when her older daughter, who just graduated from college, starts a new job and moves away.

Hard to believe the twins are in college already. I remember the day a routine sonogram revealed that my SIL was having twins "Either your baby is two-headed or you’re having twins," the doctor is said to have said.

I remember the day they were born and many days after that we spent together on the farm in California. They’re such cool people: good natured, smart, funny and fun to be around. I am very proud of them and very impressed with their decision to go into engineering. I can’t wait to see the adults they become.

The girls have always been great friends with Teen Spirit — from the moment they attached a black and white mobile to his portable crib (when he was three months and they were three). Email and instant messaging have sealed that bi-coastal friendship and I expect them to all be close forever. I hope so.

Being a twin myself, I have always felt a special kinship with my twin nieces. I am fascinated by their relationship and the ways they are—and are not similar. I always find it so annoying to be confused for my twin so I made a special effort to tell them apart. Sadly, even I made mistakes from time to time.

Although identical, my twin nieces are very different people and they have chosen to go to different colleges. This is the first time they’ve even been in a separate school (and they have often been in the same class). This is the first time they’ve ever been separated except for a few days here and there. This will be a big change for both of them and probably something of a challenge. I am so curious as to how they are doing.

My sister and I always went to different schools from second grade on up. We always had different friends and never even considered going to the same college. But I visited her college frequently and got to know the campus and her friends. It’s like attending two colleges at once when you have a twin (I hope my twin nieces enjoy that aspect of being a twin).

As for my SIL, she has a lot to be proud of. Three highly motivated girls – two in college, one on her way to an interesting career. But it must feel strange to have them out of the house — kind of lonely and sad. She sent out an email yesterday to fill the family in:

E has been having a very busy first week of orientation. She’s been touring the campus, meeting her department, bowling, kayaking, hot tubing, maybe even a little karaoke and belly dancing??? She’s made lots of new friends and found out that there will be one other girl besides her in the Materials Engineering class of 2010. After fifteen years of uniforms we’re curious what she will decide to wear…. probably t-shirt, jeans, and flip flops, the new uniform….

We just dropped off A off yesterday so she has had less time to acclimate to college life. Luckily she went second off to college as she had more stuff and there wouldn’t have been room for E in the van. (A had a micro-fridge, and a bicycle, plus everything E took. The school —a campus of the University of California—has an extra 900 freshmen this year that they guaranteed housing to so lots of rooms came with an extra roommate.

In the meantime, the recent college grad is at home waiting to hear about a new job that will take her far from home. Much excitement in that household: nerves, tears, chaos, change.

Lots of change.