My $0.02. Do not touch this job with your worst enemies ten foot pole. Nothing but trouble from the get. First off it is in a tree which is always ten times worse than in a structure. Structures can be disassembled and reassembled, trees cannot. Structures have known and predictable cavities trees do not. Structures are not living creatures that die when you cut them nor does a simple cutout in a structure usually involve a support member and risk the collapse of the structure. Almost all tree cutouts do involve either the main support member (trunk) or a large portion of it's mass (large limbs). That's just dealing with a tree cutout.
Now you have the real danger. An unknowing and unreasonable human. This lady is entirely in the wrong IMO just wanting them gone no matter what. Believe me when I say that I speak to hundreds of people just like her. This foolish woman is looking for a fool that will do as she wants based on her fears rather than seek out professional services. I will not work for idiots as almost always they are just to dumb to understand the services I provide and will blame me for their own stupidity.
This is the kind of idiot that will completely discredit the sound advice given to her by a professional like myself. Mainly because she can't believe I have the balls to actually ask for a fee my services, somehow this lazy grasshopper has got the idea that all things out the ordinary must be done for free. As a result the minute you set foot on her property she will own you. You are providing her labor at no cost, slavery by definition. God forbid the poor tree dies, it will be all your fault.
So she can't afford a professional, tough titty. Not your fault or responsibility. I don't practice medicine or law though I could if you buy into the while can't afford it sob story. I get those kind of folks off my phone as fast as possible. An old friend had a phrase that fits "you can't fix stupid".
I shouldn't even get into the application of a pesticide but I will. So your not charging, that clears you with the state but not from liability. When the ambulance chaser serves you at least you won't face administrative fines and code violations justbthe loss of everything that you have. Never ever apply a product without first obtaining the training, licensing and liability coverage that will separate your professional from your private assets. You may think "good samaritan" applies but it does not. What will apply is her insurance,if she even has any, and they in turn shall apply the full court press to you.
Oh, but it's for the bees you say. I say horse apples! It's all about you, you just can't wait to "save the bees", "show your skill/knowledge/compassion/fill in the blank". Unless your catholic and have an inside shot in Rome they ain't giving out sainthoods these days. Walk away, bees are free your labor should never be. This ain't the very last colony of bees on the planet a better one will be along in a minute.