In The Light of The Moon

After seeing multiple flying people and Holly summoning her flight powers by magical means, Lily regains Cure Moonlight's cloak and its ability to fly.

The Heartcatch Precures have an ability for their fairies to turn into these flight cloaks. However, for Moonlight since her fairy is ... well, gone after she re-obtains her abilities with the Heart Pot she's capable of summoning the cloak on her own by slapping the brooch on her dress. Since Lily is utilizing Cure Moonlight's powers from around the end of the series, this is how it would apply to her now.

It can be assumed the cloak is similar to Moonlight's own dress as far as defensive capabilities goes, as it can be pulled around to defend her to some extent as well. This is more a product of it existing though as the primary focus of it is flight.