Pediasure - to give or not to give?

ziyi's been giving me problem again. she's not eating nor finishing her milk lately. she used to eat 1-2 chinese rice bowl of porridge for lunch & dinner, some biscuits/bread/cornflakes for breakfast and a total of 22-26oz of milk each day.

now she eats 1 rice bowl of porridge for the whole day, and 16oz milk only! i brought her to the paed's office to weigh her and she's only 10.75kg at 21mo. her weight has been stagnant since her last visit to the paed at 18mo. i'm very worried and i'm not sure if i should give her Pediasure. i've consulted her doc before (few months back) and she think ziyi's doing fine and it's up to me decide whether to give her Pediasure.

would Pediasure helps since she has no interest in drinking her milk now? or am i getting too paranoid? some said it's not the figure that matters, if she's growing healthily and active, she's fine. she indeed is very very active...hyper in fact!

look at my cili padi here, so skinny minnie. only her tummy is big 'n round.