1 - Yes and yes. If she was a business instead of a private individual, would you have any doubts that it was spam?
2- It depends on the blog. Some people write for themselves and close friends, others want to write to the world at large. If it is the second case, then bloggers often push their blog on facebook, twitter, other blogs, etc. However, a mailing list is highly unusual. All blogs I know have the option for you to subscribe to them, which makes a mailing list unnecessary since interested people can just press that little button. A mailing list seems aimed at people who don't want to subscribe, which makes it rude.
3- Not in the least, as long as you do it politely. "Please remove my name from your mailing list - my inbox is already so crowded! I can get notifications by subscribing." (yes, you can but that doesn't mean you will
4- "No, I haven't. There are so many things I have to read that I just swamped", "No, I am dedicating my time to caring for the kids/work/business/church that I am behind on all my reading." (once again, she doesn't need to know that her blogs ranks just behind the cereal box in your reading priority)