I like the idea! I think it should be a large stationary plant that attacks similiar to her auto-attack;. It'd be even cooler if it had multiple vines so that it could attack multiple targets. It'd be much better than shamblers. 
Uproot has some issues. If you don't focus on it then it's not terribly useful in a match, and if you do then you've lost out on something else.
Or... Something that would make her closer to Oak/Erebus. She summons the plant that can attack things (more summons per rank) and these can convert the killed minions into shamblers. It'd turn "Summon Shambler" into something even cooler. Shamblers could remain weak, have less upgrades, but they'd be more mana efficient to produce and potentially more abundtant. This would easily give her a viable minion build (at least I think so).
If her plant comes under attack she could even shield it while it works to produce more shamblers.