Yes, you should probably talk to her.
of course it is possible you are hoping for something that can't be. The question is what she is agreeable to and what you are agreeable to. It could be that she is ok with some form of non romantic relationship and is favourable to the idea of having sex even if it is not something she wants for herself, or maybe she is repulsed by sex and not interested in romance at all, or maybe... you hopefully get my point. There are many different aro experiences and many different ace experiences and just from saying she is aro-ace we have no idea how she would react.
You say she is your friend and you also say that she knows. So you have the option of just asking her what she wants. Ask her if that relationship you want is possible and respect her response.
Sorry if this comes off as blunt but you aren't going to find out what she wants without asking her. Remember, you say she knows your interest anyway, there's no hiding anymore.
Also as an aside, I reckon you should spend time with her anyway, you know, because she is your friend.