Hi Kate,
Thanks for your question.
I honestly have never had anyone ask this before. I’m going to answer you as simply as possible.
Since we can’t communicate with our dogs in a traditional verbal sense, we have to pick up on their cues and read their behavior.
Signs a dog doesn’t want to be touched is your start to pet her and she growls, cowers, recoils, walks away, bites you, etc, then she is not interested.
If you start to pet your dog and she moves closer, moans in delight, wags her tail, nudges your hand when you stop, licks you, etc then she is interested.
You can monitor what times of day and state of relaxation she is in when she is accepting of the attention and offer her some during those times in the future.
Good luck!
Dr. Clayton Greenway