This is pretty light hearted, and obviously she can buy whatever she likes. That said:
My sister (27F) keeps buying the same things as me (36F) and I'm finding it really annoying. She is staying with my family over Christmas and since she has been here she's ordered several things that I have (think clothes, bedding, soft furnishings, plants, and even a paint colour!) and today, I foolishly mentioned that I'd managed to get a coat in the sale that I'd been eyeing up for a little while, and within minutes she'd gone online and ordered the same one!
I know it shouldn't bother me, but it does!
She made a joke saying "Gosh! I'm such a little copycat!" and I snipped back "You really are!" and she looked a bit hurt. I shouldn't have agreed with her, and I wish I hadn't said anything because she is a nice person and I didn't mean to hurt her feelings.
I can't work out why it is bothering me really. I am trying to find my identity again now that my DD is 2 and I feel like I can hold a thought in my head again, and I would really like some things to feel like they are mine, but her having them doesn't really detract from that.
I am starting to dread my sister asking where I got something or to send her links, and I know that is mean, but I also wonder if it is a normal reaction to feeling copied at a time when you really do not want to feel like another person clinging to your coat-tails?