I have been a pixie owner for over a year my male is massive for its age. but there is one thing you need to consider. just like humans frogs will have growth spirits meaning when conditions are perfect and they are getting the right nutrition they will grow noticeably, but not always. Have you ever tried to sit if front of the mirror and watch your hair grow? Because you see your frogs every day it will seem like they always stay the same size which is totally not true. measure your frog from vent to snout write it down some where and lock it away for 3-5 months. Then measure it again after that time and compare. Not all pixies will grow at the same rate. however they will continue to grow almost their whole lives, which can be 20 years. What you can do to stimulate growth is gut load and dust the frogs food. I noticed people mention crickets and super worms. I do not feed my pixies any of the such any more. However i feed my cane toads crickets but that is a different story. Here are some foods that i would suggest you use instead of crickets and super worms: earth worms, roaches of any type, mice (as a monthly supplement they come in all sizes), super worms, horned worms, minnows, and crayfish. All of these compared to crickets and super worms are like comparing kale and quinoa to Mcdonalds. This will greatly impact your frogs growth. I have seen it with my own eyes i had a pixie 2 months old that i fed nothing but roaches and earthworms to. And it grew to twice the size of another frog of the same sex i had stapled on crickets and super worms that was six months old. Also a factor may be your husbandry there is a care sheet on this sight that will let you know exactly what temps, humidity and substrate to use.