Shannon possesses strong healing abilities and moderate damage dealing abilities. She also has a rather lacklustre defence.

Recommended Passive Skills:
Auto Tanti <100% Max HP - If you have enough Elixir Tanti.
Regen - This may not sound much but it really does add up over the course of battle.

Recommended Command Skills:
Steal - It has a 100% chance to succeed and all enemies except for the repeat minions (Jormac's minions) carry items.
Medicine - While this will lock Shannon out of the support items you find (you won't get many in the demo anyway) it doubles the effect of healing items. Of particular note is that Caleran Herbs which normally revive with 50HP will revive with 100HP when used through the Medicine command.

Skill System:
Shannon learns skills by winning battles and using her skills in battles.
They are divided into 4 trees.

Healing	Malpractice	Placebo	Alternative
Start	Start	3 wins	20 wins
Heal	Bone Breaker	Placebo	Aromatherapy
10 wins/uses	20 wins/uses	12 wins/uses	23 wins
Regen	Super Drug	Amnesia Effect	Acupuncture
25 wins/uses	Not In Demo	30 wins/uses	60 wins/uses
Heal More	Not In Demo	Might not be a Placebo	Psychic Surgery
Not In Demo	Not In Demo	60 wins/uses	Not In Demo
Not In Demo	Not In Demo	Mass Placebo	Not In Demo

The most useful learnable skills in relation to the demo are Regen, Super Drug (despite the HP loss the stat boost is very effective) and Placebo.

While you are not likely to unlock Mass Placebo during the demo it is Shannon's only group heal skill in the whole game.