~In both forms~
Both Jamie and Mikani have limited telepathic abilities. They cannot randomly 'speak' to just anybody. However, through concentration and mutual consent, she can forge a permament (and 'turn-offable', of course.
) link with the mind of a friend, through which they can converse at any distance while on the same plane, and can sense emotions when within line-of-sight.
Immunity to possession
Both Jamie and Mikani are immune to possession attempts. Any attempt to possess her will be violently rejected by her Magical Girl nature (which, de facto, is kind-of sort-of 'possessing' her already, and doesn't appreciate sharing). This is not, however, immunity to mind control and suggestion, to which she is better at resisting than the average person, but is, by no means, immune to.
Jamie can cause a person within 50 feet, and with line of sight to, to suffer a sudden, searing headache for a brief period.
Jamie can project low-powered sonic blasts from her hands. These are useful as stun weapons, and for doing things like snapping padlocks off doors.
Jamie can project a 'holographic' image of herself to places she has been before, regardless of her location (and the location of the destination, even if on another plane). She can be seen and heard by those at the 'receving end', however she cannot interact* with any objects on the 'receiving end', and on the 'sending end' is in a semi-consious, meditative state and cannot defend herself. If disturbed, however, she will awaken, severing the projection connection.
*Except with certain horizontal surfaces (beds, floors, and the like). Don't ask how this works.
Earth manipulation/Water manipulation
Mikani can cause minor geomantic effects, however this puts a considerable strain upon her. She can cause cracks in the earth to open and close, cause very small, localised tremors, and can soften or harden mud and sand over a limited area. She can also cause minor hydromantic effects, including the creation of jets and fountains of water.
Mikani's favourite attack is the feared Dire Kudzu. Dire Kudzu is a vine with large, heart-shaped leaves, fragrant purple flowers...and wicked, inch-long thorns with the sharpness of razor blades and the hardness of adamantium. Dire Kudzu grows rapidly when she is creating it, and can ensnare a large creature or fill a small room in literally seconds. When she severs her connection with the vine, it dies rapidly - over a matter of minutes or hours, depending on the size of the plant - but remains dangerous until burned, or it rots.
Mikani has minor "Force-like" abilities. She can call an object to her hand over a limited distance, and is able of augmenting her jumps and other athletic abilities using telekinesis.
Mikani possesses limited "healing" abilities. While she cannot actually heal an injury, she can cause the pain of an injury to not be felt, reducing it to a feeling of "presence", as opposed to actual pain. This effect lasts until the injury is re-aggrivated in some way, or is treated.
A special case, Mikani can, in combination with other Magical Girls, channel geoenergy into powerful energy blasts, that combine with those of her companions' to produce a multitude of effects.