My husband and I are also in Schuylkill County (Pine Grove Township) and are both in the legal profession. Unfortunately, Blythe Township does not post their zoning maps or ordinances online, so I can't be much help specifically. Don't expect the police to know the laws outside, nuisance and crimes code. Don't rely on a verbal 'okay' from your Zoning Officer either.
Determine what you're zoned for. If you are in a populated area, with more homes than land, chances are you are in an area zoned Residential. If that is the case, there is a chance that zoning ordinances do not provide for poultry or livestock on your property. If your neighbors are cows(and I mean literally, not figuratively), then changes are good that you're zoned farm/agriculture and you could have chickens, cows, goats, pigs, horses, whatever you'd like. Unless of course, poultry is specifically excluded by ordinance.
You can find what your property is zoned for out at your township office or by searching the schuylkill county parcel viewer for your address and look at the CAMA which will show how your property is zoned.
Finding the zoning ordinances may be difficult, townships are supposed to file them with the county law library so that there is a public access for them, however, many townships don't do that and keep them on file at the township building.
Get a copy of the ordinance that shows you are allowed poultry/livestock for yourself and for the officer next time he comes a knocking or save him a trip and take it to them preemptively.
As far as the nosy neighbor goes, give her a warning that you will not tolerate her trespassing and that you will call the police on her next time she trespasses. I think I read somewhere where someone suggested putting up a videocamera. That's fine if you keep it to your property and post a sign that your property is under video surveillence. You don't want to get in trouble for videotaping someone without their permission (Its a crime).
I've had trouble with one of our neighbors, but there is nothing he can do, we're zoned agricultural preservation.
Good luck.