MrStinkyanswered grow question 3 years ago 2 plants, of the same strain, from the same breeder, from the same packet are going to have some genetic variation.
I am just finishing up 2 x Northern Light - both LST'd, one 35cm tall and harvest 2 weeks ago, one 55cm tall and not chopped yet - it is like comparing potatoes and tomoatoes.
Treat them as individuals now you are aware - one might mature earlier than the other and be ready for harvest a couple weeks earlier than the other, but that is alright, it means you get 2 harvest days, some dry smoke earlier on in the overall cycle and may have even got your cure on the way before the other is chopped.
Keep up the hard work!