This spider was keeping a very close eye (or six) on me as I moved around the lantana bush in which she had woven her nest. I believe she is a green lynx spider (Peucetia viridans), although she has more extensive red markings on her cephalothorax than most individuals of that species illustrated on the web (Ha! web).
Female green lynx spiders bravely defend their egg sacs and are capable of spraying venom at targets up to 20 cm away (Fink, L.S., 1984, Journal of Arachnology 12:373. PDF).
In the upper left corner of the photo below, you can see the reddish abdomens of recently hatched spiderlings, so the mother’s work is almost done.