RTI is protected, and is not supposed to be sold directly to consumers. It is not possible for a consumer to obtain a legal copy of the programming software. Personally I would refuse to program the remote for her. I always tell my customers that my price for a component is an installed price, and that the product may be found online for less. I explain that the additional product cost is profit which is used to subsidize my labor costs i.e. I don't charge for all the labor hours necessary to install the component since I am making additional profit on the equipment. I also provide full warranty support on both the equipment and my labor.

If you feel you must take the job, tell her the following:
1) You will charge full T&M for the install, which in all likelihood will negate any cost savings she realizes by purchasing the equipment on the internet.
2) Any service calls will be billed at full T&M - you won't provide any free warranty support.
3) In the case of RTI, there will be no manufacturer warranty support and she will have to pay the full cost of any repairs.

Usually this is enough to make the client reconsider their internet purchase.

If you can discover her Internet source for RTI, I'm sure that RTI would be very interested in hearing about that. RTI would most likely take steps to shut that source down if they are trying to sell new in the box RTI equipment.