Awww Sorry about your Molly! Yes it's quite possible, but more likely she had the one fry (or more) 35 days ago or he would be too small to venture out in 2 days. New born Molly fry are just over 1/4 inch or 1/2 cm. Eye balls and a tail, but a fairly substantial face with eyes. (my Swordtails are minuscule compared, longer and skinnier and quite pale so very hard to see for several weeks. My Molly had 5, then 8, then 13, not big drops. My Swordtail however had 1 (found), then 7, then min 65!!!!! and then I left her in for the next drop and I think only 1 survived.
It is very likely he is a month old unless you found him up at the surface hiding in a plant so one or 2 days old. Hope that helps figure out things. (she could have been pregnant at the store or holding sperm for months before you got Mom.)