Je l'ai fait! I finished the French skill tree! L'arbre français!
I just finished the French skill tree with all skills golden!! https://i.imgur.com/OCHrjHC.png
Some stats: I'm finishing at level 17 with 11,569 XP and apparently 2,699 words learned. Also, I'm at 66% fluent (though I was 67% a few days ago...).
How long did this take me? I started my first lessons with Duolingo about a year and a half ago, probably August of 2016 - but I had some pretty long stretches of not practicing in there (along with too many streak freezes used!). My four longest streaks were: 88 days, 108 days, 16 days, and my current run of 17 days. Along with several smaller streaks and some standalone days, I practiced probably around 250ish days averaging 46xp/day to finish the tree. (https://imgur.com/a/ukGcg)
All this is building toward a year abroad in France for my French double major in university. I leave in July 2019, so I hope to continue past Duolingo to reach "'100% fluent'" (or close enough... close enough is good) by then! I guess another goal is to reach level 25, but I'm not even halfway there! Maybe also to do the reverse French-to-English tree to completion.
Well done! I'm glad to see your full description. As I've gotten closer to finishing the tree, I've noticed that I couldn't possibly hit level 25 just in the remaining lessons, which of course also means that I'll probably be stuck in the high sixties for percent fluency. Good luck to you!