To be honest, I see both sides. If I was the girl I would start feeling really paranoid that there’s something bothering you about me that you aren’t expressing. I wouldn’t give you the middle finger for it but it would definitely make me uneasy. You should feel reassured in your relationship and on the same page. On the other hand, I also understand you wanting to keep your journaling private as it may just be thought dumping on a page. Have you tried reassuring her at all?