My massage therapist quit the spa she used to work for, and now takes clients in her home.

I don’t mind tipping at a spa, because she probably only gets an hourly rate and most of the cost of the massage goes towards the facility’s rent/electricity/supplies, etc.

My question is: If I am going to her house for a massage, how much (if any) do I tip? She gets 100% of my fee, so is a tip necessary?