How long does it take for a female Russian tortoise to mature? Well, let me clarify; how long does it take them to be fully grown? I've had daisy for a while and I feel like she hasn't really grown... She's getting her vitamins and minerals. I think it may because she's been growing so steadily that I haven't noticed. Anyway, back to the question... How long does it take for the to grow to full size? Thanks everybody! All comments appreciated!