baby barely eating

my 9 month old is not feeling well. no fever or anything i’m guessing that she’s teething. yesterday night she started waking out of her sleep throwing up looked like mucus it was yellow and a bit thick. she woke about 4 times doing that. she was fine all day today she’s playing, talking and all but not a lot so she’s like herself but not like herself. she literally had 2 bottles today and only drank half the bottle both times and her poop is extremely watery.. not sure what to do! i’m trying to keep her hydrated