Conflicted twin-ishness?

[ejarh.livejournal.com]

In Falconer's Lure, Lawrie gets upset when Nicola cuts her hair as they no longer look alike, but in End of Term she's upset at having to walk in the choir procession just because she looks like Nick. I don't have my books anywhere nearby (sob!) so I can't trace this in any of the other books, but I'm wondering which is more important for her - looking like Nick or not. Lawrie is such an individual - there's no one like her - and SHE certainly thinks she's special, unique, destined for greatness, etc. - so her huge upset over the hair making them different seems a bit strange. In fact, you'd think she would be the one to cut her hair first. Thoughts, insights?