Just found out that it is the Blue Nawab caterpillar(Polyura schreiber tisamenus) .
I am very sure it has something to do with the spiny growth below the rosella flower bract. Somehow i think it might be trying to mimic the look but the rest of the body gave it away. I was fooled for a moment though, thinking it was a piece of fallen leaf that a caterpillar had chewed off from the torch ginger above the rosella. Then i noticed the strange "horns" and the body.
And also not forgetting the sqarish flap at the rear, like a lobster's tail.
What kind of butterfly will it turn into? See this link: http://butterfly.nss.org.sg/expert/Polyura-schreiber/polyura-schreiber.htm
The star fruit tree in her front yard is very old and produces lots of sweet star fruits.
The chiku tree is also very big with a very thick trunk. Part of the reason for the very good quality of fruit may be the soil, which is dark brownish black in colour, instead of the reddish clay type soil in singapore and some parts of the region.