Our girls always shared a room. In part, it was because most of our family lives at a bit of a distance and it worked for us to be able to invite them for the weekend, for dinner and a sleepover, whatever.
Partly, though, our kids shared a room because think it's an excellent way to learn how to cooperate with others, how to give in when needed, how to stick up for yourself, how to compromise and how to communicate (sometimes at great volume -- but they do communicate!).
Fortunately, their bedrooms are large enough that they can have their own space-- sort of. It takes a great deal of negotiating on their part -- and on yours-- but it can work and work well. Daughter #3 is home on her first college spring break and one of the conversations we've had is how she finds so many of her peers don't know how to live with another person. She, on the other hand, settled right in to life with a room-mate because she's walked down that road for years. And yes, all 4 complained many times how they wanted their own rooms.
Good luck. What works for one family will not work for every one.!