"I do wish you guys would take a little more time with this decision," she writes, addressing the recently reconciled couple on her blog. "I certainly do not understand why you are rushing things. Unless of course there is some reason for the hurry."
Offering her congratulations, Mercede writes that she hopes Levi thought carefully before proposing and that the engagement "is a sincere decision" which "will bring you happiness."
Given their tumultuous past, Mercede writes that the engagement between Bristol, 19, and her older brother, 20, is "odd," though she couldn't be more thrilled to see the couple's 18-month-old son back in Levi's arms.
"I do know that it will be good for him to have both of his parents back in his life full time from now on," she writes.
Mercede also says she and mom Sherry would love to pitch in with the wedding planning – that is, if they're even invited to the ceremony.