Ann was registered at UW in extension courses from August 1961 until she actually attended classes in spring of 1962. She was still in WA state in fall of 1962.
Neil may have known Ann but I think he knew her more so after Obama Sr had left the island. He mentions he would often see Stanley and Jr walking in the area, while Ann was in classes. Which home were Madelyn and Stanley living in which you mention, the one on Kamehameha Ave or the one on University Ave.?
It was on Kamehameha Avenue, just down a ways from the corner of East Manoa Road.
You could well be right about when Neil Abercrombie would have had more opportunity to know Ann Dunham. Barack Sr. would often be present at Charlie’s Tavern on King St., which I where I knew him from in 1960/61, but I never saw Ann Dunham there.