Why would she remind me of her birthday?

Well, I've been talking to this girl a fair bit, and she has reminded me of her birthday twice, several months apart

First time was reasonable enough. She asked me when mine was, and then said hers. (Also was one of the two to actually say something on my birthday)

Second was a bit more specific. We were on the topic of plans over break, and she specifically brought up her 21st birthday being 2 days after x-mas.


Probably over thinking it, but their might be something there?
Why would she remind me of her birthday?
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