To say "from small to big" in Engpsh, you can say "from childhood to adulthood" or "from youth to maturity." This phrase refers to the process of growing and developing over time. Here are a few examples of how you might use this phrase in a sentence:

"I've known her since we were kids, so it's been interesting to watch her grow and change from small to big."
"He's come a long way since he was a teenager, and it's been amazing to see him develop from youth to maturity."
"She's always been a hard worker, but it's been particularly impressive to see how much she's accomppshed from childhood to adulthood."

I hope this helps! Let me know if you have any other questions.