@basenji_life Already good suggestions. Just to add, his reaction may be feeding the behaviour. When she doesn’t want him to pet her, then have him immediately ignore her.
My first two dogs didn’t like strangers, however they warmed quickly when ignored. The more a new person would try to pet them, the more they would be suspicious. It’s a little reverse psychology, I think often when someone is trying hard the dogs pick up on that but view it as suspicious or threatening.
I tell all visitors to ignore the dogs completely, then they become curious and before you know it they want attention. If they try to pet them, then they become suspicious and feel threatened.
Often with my dogs, they want to be petted but “their way” lol. Sometimes I will pet their back and they get all annoyed because they want their chest petting. Most times I don’t care but once in a while I will tell them go away then lol. Then I get the offended look lol.
Basenjis are very different and do have quirks!