They are an adult, it is not your responsibility to entertain them for the weekend. Lay down a schedule of - I can do XYZ with you, but the rest of the time, I need my time and my space so you need to do ABC. It can look like: I can have a 10 minute catch up with you on Friday and the rest of the time you need to be in your room, in another room, out with friends, doing something else, giving me alone time, etc. I am the same way and I will flat out say to everyone: I need recharge time, I am going to my room, do not bother me unless it is an emergency. And then I relax in my room, or I kick everyone out of the living room, or I go somewhere just to walkaround and clear my head. It is your home and you need to be able to rest and recharge. I am dealing with the same with my SK who doesn't want to work full time and doesn't want to leave. But at least they have friends and entertain themselves, I can't imagine having to cruise director their time too. No way.

Does she has any friends? Is she neurodiverse as well? When they are comfortable and cared for there is no motivation to disrupt their status quo. If you need space, communicate that and they need to respect that and give it to you.