My neighbor left her house over 6 months ago, no payments, house is trashed out. Can I file for squatters rights? No taxes haven't been paid.

It depends on where this is (what state, in the US?), but generally they answer is going to be no. For one thing, you'd have to openly use it, and for another, it would have to be for several years, often 7 or 10 or even more. The town will have put it up for sale for back taxes long before then. If you want to shorten the time all this takes, call the town and have it condemned if it's truly trashed and a health and fire hazard.