Why are my baby Peaches falling off?

that's a possibility... or I read something about a peach borer.

 

Another page at UC Davis lets you select your own pest, http://www.ipm.ucdavis.edu/PMG/selectnewpest.peach.html

Jerry

 

the only one that seems possible is the Brown Rot Blossom and Twig Blight... but only because it mentions some seepage from the fruit. The branches and leaves all look very healthy.