Her Q feels like Brand's W to me in terms of damage, dealing only 19 less base when targets are ablaze, with the same AP ratio, it also costs a lot less mana. In addition to that, it's somewhat harder to predict where it will land (more or less compensated by a smaller radius) and gets a 1.25 second aoe stun..
Her W lets her win most trades, may not have the best burst or heal but is definitely not the worst. The bounce range is even longer or the same as her cast range, which is pretty damn good. Like all heals, this can consume your mana very fast, but you have to keep in mind that the damage portion is not that bad, easily justifying the costs.
Her E is in my opinion her weakest spell, but only because the other spells are so very strong. In lane this will not be as useful if you play her as a mage, but it gives great chasingpower lategame, combined with the movementspeed her passive gives to whoever she buffs.
Her R is what makes her ganks deadly while far away, or lets you hit your combo easily in lane. It's almost exactly as wide as the Baron pit's entry, making it one of the best if not the best initiator for a baron fight. The slowness of it doesn't really make up for how wide it is, making it impossible to dodge at closer range, although fairly easy at long range, assuming it wasn't coming from fog of war.
Awesome AP ratio, decent base damage and a 3-5 second utterly crippling slow.
The only saving grace is that her cooldowns are not that great. However, this doesn't really matter as much after she hits level 6 and can burst very hard. Her teamfight presence is absolutely devastating and this is where she really shines, dealing tons of damage with her ultimate.
Great damage and great cc only leaves room for mediocre escaping capabilities in the form of her passive, which is obviously still better than nothing at all.
I expect nothing but very harsh nerfs.