I've been around, dude. It's a long story, but I'm back now.
You can clone her by snipping off a branch that has grown to about 3-4 inches in length.
What makes you think it's too late? Just remember...the only way you can tell if the plant is female (and even WORTH cloning) is to put it into flowering (or wait until it shows preflowers, but that could take a month or more).
At this point you can clone your plant (now you can be 100% sure that the clone will be a female because it's a CLONE OF A FEMALE), and you won't have to worry about sexing it, so if you want, you can leave it in vegetation for however long you want because no matter what, it'll be a female! Why? Because it's a CLONE (copy) of a FEMALE!
If it were up to me, I'd grow a plant until its branches were "cloneable", then put it into flowering. Once I know it's a female, I'd take 1 clone and start a new plant (guaranteed female). This way, I can have the original plant in flowering while the clone can remain in veg for however long I want! Then just before I decide to put the second plant into flowering, I'll take a clone of and leave the clone in veg! It's a beautiful cycle...
If you have any other questions, feel free to ask!