I agree with the above post. Our manager would have informed our team about an absence. The details are nobody's business obviously.

It sounds like she was trying make her concern sound work based when in fact she was probably just a bit curious,maybe even wanting to ensure you were ok without asking directly.

I think sending the text to your boss would probably cause you to come across unfavorably, imho.
From the outside it just doesn't appear like your co worker did anything wrong.
As the previous poster said, it seems your intense dislike for this person, taints your opinion of everything she does.
Must make th working environment stressful.

Hope you find away to not feel so effected by your colleague. All the best.