I would say at least a month maybe longer. The bud is not filled out at all. These look like they have only been in flower a couple of weeks to me but it is hard to tell when you can only see part of the plant. The trics are all still nice and white so she is still growing...give her some time.
Alright Ill toss mine in here for a guestimate, this was taken a couple days ago with that in mind...
while it appears that theres strong new white hairs growing all the time, but there its got to be at least 60% red to 40% white hair if not actually moreso like 70-30...
I dont have a scope to check the trichs and its a rescued plant from a friend who got caught by landlord its never been on nutes or anything... when I got it from him about 2 weeks ago he had it under an incandescent light. ( I almost crapped my pants due to its mistreatment ) eitheway,
dont mind the burning in the forefront it was there when I got it and I have it under proper lighting atm,
since its a rescue I have no idea how far into flowering it is...
so guess away
After looking at the blow up of the last photo, it looks like about 35% ripe to me and harvest at 50% so from the last bud photo, I would say it could be ready very soon...maybe now for the riper buds.
I harvest as they get ripe and let the small imature buds get bigger and ripen up but I am no longer growing myself.