anita isn't asking how she can get a pb in super special conditions
it's a similar thread to lao's except i don't feel it's worth me offering advice to him when he's a much better windsurfer

any way i'm in a similar boat to anita, i weigh 55kgs and have mostly slalom kit to choose from probably most importantly no speed boards
the first time i broke 30 was a insanely fresh seabreeze on my smallest possible gear but in very lumpy water at pelican point since then i disagree that small is best my 6.2reflex and 57cm mistral and a soft 30cm pointer is just about the easiest kit for me to get over the 30 mostly because my 5.0 isn't any faster until it is properly windy and secondly the less extreme conditions often mean a tad flatter water
as decrepit said board trim is also very important for light weights, foot straps should be nice and close together (no need for mods) and the board should be trimmed flat yet it is important you still have enough fin to fly the board.
all up i think your extremely close to the regular 30's anita with just a bit of tuning and different gear selection you will be ready for when we do get some wind
and last of all if your really desperate a bit of lead in your life jacket can help when you are over done but this does make everything but straight sailing alot harder and therefore sessions can be shortened alot hope this helps