The lawn care company coming is probably the high point of her day. They get lonely and will even call 911 for somebody to talk to. Also, she said it was an all day job because she very well could be the kind who stands out there watching you and will be unreasonably picky. Who was trimming her bushes before? Good luck.
Price fairly but price to stay in business.
You can't charge extra because it takes you twice as long to do the job because you have crappy or outmoded equipment.
And, if they don't pay, put a shovel upside their head.