i think the opposite really. i think she's really been thinking about it and is very aware of "something" happening but she's really embarrassed and doesn't know how to deal with it.
If she hadn't thought much about it, we wouldn't have gotten the tsudere page and she would have just given it to him casually.
If anything, I think she's probably giving it more thought than Shunpei as she's probably an overthinker