On the other hand, nobody can say the risk is zero, especially with repeated open mouth kissing. Is your kissing partner on
treatment for her HIV
infection? What is her
viral load (the amount of HIV in her blood)? If on treatment with a low viral load, any miniscule risk will be even further reduced. In any case, to be maximally safe, I would recommend you have an HIV test from time to time, like once a year.
Other STDs also are not transmitted by kissing, with few and rare exceptions.