i'm 5'2 1/2, and l weigh around110 pounds. all terrains.

for reference i'm 6'2 175 and l have 58.
so for you l would say somewhere in low 40s. 140-144 or so.

Get a board thats from chin to nose

Three things matter when choosing a board: your weight, your ability, and the type of terrain you're riding. Height does not really factor in. For your weight l would look at anything 140-144 cm.

For more explanation, dogfunk recently released a pretty good sizing guide here: http://dogfunk.com/dogfunk/dc/548/Dogfunk-Snowboard-Size-Guide.html?sssdmh=dm10.106690&cmp_id=EM_CON3027a3&mv_pc=r202

maybe 140. somewhere around that