Pam, I was a travel consultant for 35 years although retired for 4 years. Looks like you covered everything. Just as a suggestion I would ask one of Lauren’s Docs if he knows anyone even just a GP Doctor in that area in case Lauren needs to call. I know Riviera Maya is about a 45 minute ride from Cancun which may be a better place to look for someone.
I do know they will have a fabulous time, its a beautiful area and only about 30 minutes from the Mayan ruins. One last suggestion, don’t drink the water! LOL
P.S. Last August I traveled with all my Diabetic supplies like Insulin. Had no problem at all as long as in original bottles.