K.,
While I agree w/ you that your MIL is annoying and hardly a pleasant person, she really didn't do any damage by telling your daughter that you eloped. Of course you and your husband should have been the ones to tell your daughter that, but I am wondering why you haven't told her? It is a shame that your MIL beat you to it. Did she know that you and your husband haven't told your daughter, and have you and your husband ever asked her NOT to tell your daughter that information? If she knew all of that, she is very devious and manipulative. But if she didn't know any of that, she is not really to blame. This in no way will destroy your daughter's love of princesses. Your daughter will choose how she wants to be married when she is all grown up and I PROMISE you that your MIL's conversation with her about you eloping will have NO bearing in her decision whatsoever!! Your MIL did no damage to your daughter at all. However, she might have done some damage to her relationship with you and her son (especially if she knew you didn't want your daughter to know that you eloped). If your blood pressure truly rises when she visits, here are some natural remedies to lower you blood pressure (I googled it and found a webiste called www.prevention.com).
1) Take power walks
2) Breathe deeply (yoga, meditation, etc.)
3) Eat potassium rich foods like sweet potatoes, tomatoes, orange juice, potatoes, bananas, kidney beans, peas, cantaloupe, honeydew melon, and dried fruits such as prunes and raisins.
4) Cut down on sodium
5) Eat some dark chocolate - have 1/2 ounce daily (make sure it contains at least 70% cocoa
6) Take a coenzyme Q10 supplement. In a review of 12 studies, researchers found that coenzyme Q10 reduced blood pressure by up to 17 mmhg over 10 mmhg. The antioxidant, required for energy production, dilates blood vessels. Ask your doctor about taking a 60 to 100 mg supplement up to 3 times a day.
7) Drink a little - Women's Hospital, for example, found that light drinking (defined as one-quarter to one-half a drink per day for a woman) may actually reduce blood pressure more than no drinks per day.
8) Drink hibiscus tea - people who sipped 3 cups of a hibiscus tea daily lowered systolic blood pressure by 7 points in 6 weeks on average, says researchers from Tufts University.
9) Go decaf (I would never do this, LOL!)
So, in summary, drink, eat dark chocolate, and eat bananas when your MIL visits (at least you'll have a good excuse to drink and eat dark chocolate!) Seriously, your daughter is fine! Sorry about your MIL. Mine sucks too.