I would put it off for another month or so before you go down tube feeding path, my dd was born off the top of the charts and at the 13.5months is the same weight as your dd, she has been hovering around 8 to 8.5 since 11.5 months.

Some kids don't eat heaps and are happy without it all.

My neice who is 6 and will be 7 in november is only 14-15 kilos now. And she was a picky eater as a bub and is healthy she is just a little girl.

Are you tall/large build, because if you are a small build and dh then myabe dd will be to.