Well, the Guides have the problem of not showing a number of
Side Quests that seem to exist as requirements/intermediary steps to be solved in each character's questline. I can't remember the specifics right now, sorry for that, but my guess is that you haven't bumped in theirs yet.
- For Ms Brenda try to do a normal school day (no skipping, study, etc) and talk to her whenever you can, morning, noon, afternoon, to see if something new opens up.
- Visit Nancy multiple times of the day, morning before school, afternoon, evening (weekdays, even if her husband is around). Some new scene/dialogue should come up and after that things should open themselves to you, i think.
If you still have problems i might try a partial reply to find out whatever is going on.