Have you heard of Thumbtack? It's a job-matching service for all kinds of professionals. Both my husband and I get work in our respective fields through it, and have for years. It's free for you, and the professionals bid on your job if they are interested. You should word your request carefully, restrict it to the area where you will be of course, and indicate the days you're thinking of. Explain a little of what you're looking for (casual shots, outdoor shots, studio shots) and then up to 5 professionals can bid on it. (They pay to do this; you pay nothing.) You may get bids by the job or by the hour. When I bid, I explain in a cover letter what's included and how I work.
You won't get more than 5 (Thumbtack limits) so it's manageable, and you will get links to their websites and be able to see their work. They should have references on their Thumbtack profile, both from independent clients and from those they have gotten through Thumbtack. Most of us use templates for the bid letters because of the 5-bid limit, so they are sort of form-letter style. Once you read a bid, the pro gets a notification that you have done so, and they may follow up with a personalized note. Don't be offended by this - it's a good thing. They aren't trying to be pushy - it's just that they realize the rush of a template note leaves something to be desired. You can respond with more questions if you want.
You can pay at the time, either with cash or by PayPal or some other agreed-upon method, and you may well pay something up front and then more when you order additional prints. Negotiate it. I doubt someone will rip you off, but you have some recourse through Thumbtack. If a pro has had good and verified reviews through Thumbtack, you have little risk. For my husband (advertising writer) and me (proofreader/editor), the risk is with us because people can take our work and not pay - our only recourse is to have them banned from Thumbtack in the future. So the customer (in this case, you) has all the cards - with the obvious exception of getting crappy pictures and no chance to get the family together again. But remember that most photographers are happily busy at this time of year and anxious to make money keeping customers satisfied.