My sister is 12 and theres somthing coming out of her What could it be?

my sister is too afraid to tell our mom. she said that it is in her and it hangs. she said it was lumpy and brownish pinkish. it sometimes sticks to her underwear and when she wears bathing suits it hangs down. i have not seen it at all. but she's is really scared. can any one help me?