i dont know if my kitten is male can u help

i got 2 kittens for my daughters for xmas i thought they were both girls
but i now think one is a boy they look the same under the tail how else can i
tell

welcome to the site

why do you think one is a boy? are they mating? how old are they? are they neutered? and most imprtantly, can you ask your daughter?

This website might help a bit

http://www.pawsonline.info/sexinga.htm

Lift the tail. If you see TWO items from top to bottom, anus and vagina, you have a little girl. If you see three items, anus, testicles, and penis, you have a little boy. I would have assumed that you should have taken these kittens to the vet by now for shots. They should have sexed them.