In the documentary the current Kumari's family (well, mother and siblings -- IIRC there wasn't a father on the scene, although I may be misremembering) were staying in the same building. There were some interesting interviews with her siblings about relating to her as both a sister and a goddess.
I hope that it is the case that the family stay close by. But she will obviously be deprived of a normal upbringing. I wonder how a small child would cope with being venerated in this way. My dd aged 4 (PFB and only child) thinks she is a princess and that the world revolves around her. We are trying to teach her that unfortunately it doesn't. But for this little girl it looks like this will be the case. I forsee some tantrums!
We "saw" the/a previous living goddess when we went to Nepal. She lived in a beautiful palace and looked out of heavily ornate windows (so you couldn't really see her). Kathmandu and Nepal in general is a fantastic place, very rich in custom and tradition and with very lovely people. It is a massive honour for her and her family, but I agree, not really a "normal" existence.
When they retire they go back to life as normal. It is very difficult for them to adjust as they have been living a life of luxury and then they are back into the family home where they have to help with the chores, farm etc and its quite a poor lifestyle (financially). Most struggle with it. Also its considered bad luck to marry an ex goddess so they struggle to find husbands.