1) There is literally no evidence that she poisoned him.
2) There is literally no way (save a time machine) to find out whether or not she poisoned him.
3) There are plenty of respectable sources that both Shia and Sunni agree on that show that the prophet loved her and showed her a lot of affection.
4) What purpose does it serve to propagate or start rumors about her without evidence that doesn't exist and is unobtainable?
5) How will this information affect how you practice Islam? If you are Shia you like likely already reject hadiths reported by her, and if you are Sunni you likely accept hadiths reported by her. And if you're trying to decide whether to be shia or sunni based solely off a matter that is unprovable at this point in time, then I think you need to reevaluate.
Sorry for not answering your question. My guess would be that I highly doubt it.