POWERS: Jubilee is a mutant with the superhuman ability to generate energy globules in varying degrees of power and intensity. These globules are basically powerful fireworks, varying in intensity. It is known that at the full extent of her abilities Jubilee was able to demolish a large building from the inside. At the other end of the spectrum are fairly weak 'paffs.' These plasmoids obey her mental control -- traveling where she directs them; arranging themselves in balls, streamers and other shapes; and exploding as she wishes. Effects range from a multitude of colourful sparkles that can temporarily blind onlookers to a fairly powerful detonation capable of smashing tree trunks and metal objects. Jubilee can absorb her "fireworks" back into her own body without harm to herself.  Her control varies - when she is annoyed or upset her plasmoids tend to be rather more powerful, but lacking in control. When she is calm they tend to be weak and fairly ineffective.

For an in depth and very knowledgeable explanation of her powers go to this specific forum thread. Be warned, its quite long and VERY thorough!!