Imagine having a tree burst out of the ground to punch you or a giant Venus flytrap eats someone as the super? There could be a pollen stun move.
Hell ever her winpose could be epic, tree branches form a swing together under her butt and lift her up, kinda like a Quan Chi/Killer Frost win pose.
It'd be boss.
I like the way you think.

Yes! I have always imagined her super move involving a Venus Fly trap basically eating them (then the camera takes you inside the plant showing them getting stabbed with thorns and what not) and then it spits the opponent out. Some other moves I've thought about:
1.) A pollen like stun (like you mentioned) ala Sonya in MK9. Like she blows a kiss and it stuns them...or make this a parry.
2.) A move where she stomps the ground and vines come out of the ground (kind of like Grundy's swamp move thingy) and if you MB the move it will hold them in place and you can attack.
3.) She can control where the vines come out of the ground (close, mid, far)
4.) Her trait would be like Frost's...where you have to charge it and then when released she glows pink/purple (venom) and has super armor and a damage boost for however long
5.)Her win pose SHOULD def. be like QuanChi's/Frost....I like your idea about the vine swing and she could just laugh and look all psychotic while swinging...OR...have vines come out of the ground and hold the opponents arms and legs (like Skarlet's fatality) and she just saunters up and stares at them; laughs at them; poses.
LMAO...I love how we are nerding out over Poison Ivy in a SuperGirl thread!