Are my mollies even growing? Should they be bigger by now ? If I give them betta bite granules to widen there diet variety will that speed up there growth ? Here's what they look like now
How often do you feed? With fry you would probably want to feed a little 2-3 times a day but, at 23 days old, they are likely past this.
I don't know that feeding "Betta Bite granules" is the best option as they are formulated, as far as I can see, specifically for Betta's. Different fish species require specific nutrition for the best health. Flakes are a good base for mollies but to widen the feeding options take a look at the following link.