Write it anyway. She won't think it's weird; it's just a polite, friendly and considerate thing to do. Later, when she gets better and starts going to classes, take a moment and start talking with her. Try to look slightly embarrassed and awkward - girls actually like that, and I don't think you'd have much problems with looking that way. Tell her - "hi, I just wanted to ask if you received my card", then "well, you know I thought I ought to show you support, you know", and then go for the bullseye - "But actually I've been wanting to, you know, get to know you for a long time but I just couldn't come up with an excuse and now I guess I do have an excuse - and look at us, we're finally talking!" and then go from that point.
Do I really need to spell it all out for you?
PS: Nice quads.