Helpppppp idk wat to do!!!!!!!?

Ok sorry if this is kind of long but ok so i have a friend (tasha) that i have been friends with since i was 4 . Any ways i told her that my other friend(katie) was kind of 2 face sometimes and tasha went and told her during 5 th period ,,,she always does this kinda stuff. And then once i asked why she did this she told me that wen i told her that katie was 2 faced i never told her not to tell katie. IDK wat to do because she is always like this and our parents are best friends (were 15 btw .) So what should i do???? And sorry for this being so long:)