From 11:00PM PDT on Friday, July 1 until 5:00AM PDT on Saturday, July 2, the Shmoop engineering elves will be making tweaks and improvements to the site. That means Shmoop will be unavailable for use during that time. Thanks for your patience!
These two couples are Mary's friends and she goes to visit them while Fanny is away in Portsmouth. Edmund doesn't like her friends at all and sees them as part of the "evil London influence" that ruins Mary's character. Interestingly, Mary doesn't always appear to think too highly of her friends, either: she gossips about them in her letters to Fanny.