I agree with above. This is not a risk for HIV. People only get HIV inside the body, such as when they have unprotected vaginal or anal sex or sharing IV drugs. Air inactivates the virus. You wouldn't get it from your shirt in any way. This is zero risk so rest easy.
Your situation involves personal contact with an object in air (that caused stains) which is not a risk for hiv. No worries, because you can't get hiv from personal contact except unprotected penetrating vaginal or anal, neither of which you did and you didn't share hollow needles to inject with which is the only other way to acquire hiv. Analysis of large numbers of infected people over the 40 years of hiv history has proven that people don't get hiv in the way you are worried is a risk.
HIV is a fragile virus in air and saliva and is effectively instantly dead in air so the worst that could happen is dead virus rubbed you, and obviously anything which is dead cannot live again so you are good. Blood and cuts would not be relevant in your situation since the hiv has become effectively dead, so you don't have to worry about them to be sure that you are safe.
You run a serious risk for coronavirus though because she may have it, so I would avoid this activity.