Can toxemia cause parkinson's?

No evidence it does. If by toxemia you mean what physicians call preeclampsia or the hellp syndrome, there are no known associations with parkinson's disease. If you have seen a familial link, let your physician know as it may lead to an interesting discovery.
Unrelated. Preeclampsia is an disorder of pregnancy resulting in poor placental function and diffuse vascular malfunction that resolve with delivery. Subtle memory and attention deficits are detectable decades later, but no link exists with parkinson's disease (a progressive neurodegenrative inherited disorder).
No. Toxemia (preeclampsia) is a vasoconstrictive dirorder of late pregnancy with few if any noticeable long-term residual symptoms. Mild memory impairment and difficulty focusing can be seen years after eclampsia, however no link to parkinson's has ever been made. The latter is a neurodegenerative condition with genetic underpinnings, although undiagnosed hypertension can cause its earlier occurence.