Wachusett Street is the same as Rt 31, though it might only be called Wachusett St in Holden, not sure if it stays wachusett street when you cross into Princeton. RT 31 runs parallel to Brooks Station Rd. If you go south on it, you have to take a left onto Ball Hill Rd to get to 31, right would take you toward Rutland. (Which is where the Heifer Project is. BTW this is an international organization who works on getting livestock to villagers in developing countries so they can feed and support themselves. It's under the whole premise of "you give a man a fish he eats for a day, you teach a man to fish he eats for life", it's a pretty cool organization but very off topic).
If you go north in Brooks Station Rd, you go right at Boylston St which takes you to the center of town and the rt 31 junction.
As far as where people work....most people in Princeton and surrounding towns, don't work in town. These are mostly bedroom communities. Most people work in the medical or technology fields and travel to Worcester, or Framingham, or even as far as Boston to work.
Businesses that do exist in town are a few Xmas tree farms, a knitting store, an antique store, an old farm house that use to be a resturaunt that's used only for weddings now, 2 resturaunts, the ski mountain, a small market, a pizza place, a weird ice cream place, a bank, perhaps a im forgetting one or two things, and then town utilities offices, which all butt the light dept are located at the town center.
It's a fairly affluent community but it's small, rural, hilly, and beautiful.
Specific locations:
Her Body - her body was found on the end of an old road called Connors Lane. You can see it on a map. Her body was found along that road roughly 100 ft in a believe (but various reports differed in distance from Rd) - right side of Rd, going north.
Her Moms house is on the same side of the road as Connors lane, and is angled sideways and has 3 dormer Windows on the 3rd floor, which makes it easy to find on a map.
From what I can tell looking at the map, it doesn't appear any home would have had a clear shot of her mothers home, or of the path she was found on. The foliage btw homes appears thick, and would have been at its peak of denseness in early August making visibility even more challenges to watch someone from your home, at least I'd think.