Honestly, it sounds like you've done everything you could have as well as possible. If its only one woman complaining - and it sounds like this is probably the first complaint about you anyway - since you already covered the existence and safety precautions of your snakes, and have behaved totally rationally, I think you'll be fine as long as the woman doesn't raise a major fuss or your landlord is a jerk. Just keep doing what you've done, maybe even ask the woman if you could have a sit down so she can talk to you, hopefully maybe ease her mind about the snake a bit.

Good luck!