It's difficult to tell for sure from these pictures. I'd try to get some clearer with better lighting when you can.
My best guess is it's a young female. Female lyretail livebearers have elongated analfins and dorsal spiking, and this one isn't actually all that long. A male lyretail's gono will be VERY long, sometimes reaching the ends of their caudal fins, and will lie flat against the body just like a regular gono.
Ah, still very young then. I'm not 100% sure on the growth rate of mollies, but this fish may be yet to sex out.