I would watch out for any coach who promises starting positions or guaranteed playing time. A good team will be one where the players compete for their spot. Not get lazy because they know it is theirs. You want a coach who will challenge the girls and make them better. I don't know how important strength of schedule to you is, but it is a big one for us this coming season. Thankfully, DD's coach wants to chase PGF and ASA/USA as second year 14's with some beginning showcasing thrown in.
Don't discount a parent coach just because they are a parent. There are actually some very objective, fair parent coaches out there who do a great job. I would say, if you get a bad vibe, trust your gut. Also keep in mind that one person might love one coach while another person hates that same coach. Tastes and preferences are all very individual. Tell your DD to just go out there, relax, be confident, be friendly, encourage others around her, hustle, and have fun. If a coach sees two girls with similar ability but one has a great attitude, guess who gets the spot?