I would ask her about her behaviors (eg: instead of interrupting them or judging them which is, for parents, a totally normal response...)---ask more about things she does (in school, with friends, etc) and thinks about. She is old enough for this and is clearly looking for a response from you (vs a reaction---or, she may be looking for a reaction but she needs a thoughtful response(
You describe this as a change. This makes it significant. At 7yo kids also start to notice that words can have more than one meaning, they may begin to "get" jokes they did not before, or see the "double meaning" in behaviors or words----so there is an awareness of sexuality without real understanding except that it is "a Big Thing" in our world.