Regardless of your gender and the gender of the person you’re hooking up with, there is always going to be some level of risk of contracting HIV, or any other STBBI for that matter. But to answer your question specifically: yes, HIV is a risk for lesbians and women who have sex with women. The risk is lower (because less bodily fluids are exchanged between women) but it’s still important to try to practice safer sex methods like:
not sharing sex toys (or use a condom and wash the toy in between each use);
using a dental dam (or a cut open condom if you’re in a pinch) when performing oral sex; and,
avoid oral sex if you or your partner have cuts in/around the mouth or is menstruating
Following these harm reduction tips and getting tested regularly can greatly reduce your risk of acquiring HIV or a different STBBI and help you feel safe and secure while having sex.