so you vegged her for 8 weeks and now shes been flowering for 5 its true vegging a plant longer can decrease the flowering time but I dont think by this much I would have a look at other spots around the plant I would smell them and look at the amount of trichome development I dont really care about maturity at week 5 I just want volume I want alot of trichs if you tick all those boxes then yes maybe shes ready but if she is a sativa I can tell you from experience they take a hell of a lot longer to mature even longer than nearly all indica strains. I would keep her going an extra 2 or 3 weeks in that time she will probably put on alot of weight and mature :)