At first when I saw read this I was like wtf. Then I realized I actually know an ISFP like this. He does the whole monologue thing and doesn't realize people really just don't give a crap about his long ramblings. In my personal opinion, I think you should be honest with her. Once I was talking to an ENTP enneagram 8 friend of mine and I asked him a question and he was like, "Why are you asking that? It's so boring." I really appreciated the honesty and after that I relaxed so much more around him because I knew he'd be real with me and because I didn't have to worry about being boring because if things got boring I knew he would just tell me outright and we'd talk about something else. I hate it when people humor me when they're not really interested. ISFPs can be sensitive but I wasn't bothered at all when he said my question was boring. It was a really refreshing thing to hear. I hate politeness...I'd rather people just be real with me.