In chapter 7, Jane Bennet was going to go to Mr. Bingley's household and Mrs. Bennet said to go on horseback even though she knew it was gonna rain. She did this because she knew that if Jane went on horseback and got really sick, she would have to stay at his household for a little while until she was good to go back home. If she stayed at Mr. Bingley's household, Mrs. Bennet knew that they would most likely talk more an get closer. Back then staying at a house with a man was not very likely to happen, and if it did it was for probabaly about 20-30 minutes. Mrs. Bennet in other words was not worried about Jane getting very sick. In fact, that was her goal.
Hope this Helps! (:
