Stonerdanswered grow question 4 years ago I usually wait until the new growth shoots are at about 2-3 inches long (5-7.5cm) before tying them down just to let them develop and mature enough to handle the stress.
This is very subjective depending on your desired result and how much you intend to maintain her daily (the earlier you tie her down then the more frequent you'll need to readjust)
Hope this helps! good luck and happy growing!