<em>Moaning Myrtle's </em><u><em>sneakers</em></u> light up when she runs.
There are a couple of errors in the sentence. Moaning is an adjective describing a particular Myrtle (one that moans).
Myrtle is the one owning the sneakers. Normally Myrtle would be a noun. It isn't. It's a possessive noun. Myrtle is a possessive and requires an apostrophe.
It's happening so much that it isn't news anymore and also since is happens a lot people don't even know whether it's true or not, therefore people dont act and then again it happens,
