First, typically LLC's do not have officers (usually paid execs who may or may not own a piece of the company that run the day to day operations of the company, e.g., a CEO). However, LLC's do typically have "managers" which for all intensive purposes are equivalent to CEO's. Your first question should be whether or not you want your friend to participate as a non-equity player (i.e., she has no ownership stake in the LLC). From your question, it sounds like this is the route you wish to take. However, that may be a more complex road, which will certainly require edits to the LLC operating agreement if there is no language on the power of managers and the LLC members' ability to dismiss the managers. Moreover, it could be that you simply want your firend ot be a joint owner, which in many cases will give her the same rights as you (depending again on the terms of the operating agreement). While this may be a simpler approach, there is still paperwork that needs to be tended to and the operating agreement will need to be signed off on by her.
Given the fact there are no "one size fits all" approaches to this issue, it might make sense to consult with a local business attorney.
I hope this helps.
Disclaimer: This answer is for informational purposes only and does not constitute general or specific legal advice, nor create an attorney client relationship.