Fraxel is an elective procedure, so everything should be done to prevent complications. I recommend at least 3 days post waxing to guard against possible irritation to the follicular units which are so important to the re-epithelialization after resurfacing. Bacteria can also be introcuced with waxing and waxing might increase the chance of milia formation during the healing stage. I would wax and wait, or do the waxing at least 2 weeks after Fraxel, when the skin looks normal again.
I usually recommend patients avoid waxing for atleast 1 week before the procedure and 2 weeks after the procedure. That being said, if you didn't have any issues after the wax and your skin has had 24 hours to "recover" you should be fine with the Fraxel procedure. I would, however, mention the waxing to your provider.