Gaia, 19, from Langton Matravers, Dorset, disappeared from nearby Swanage on 7 November.
The arrests came after police searched two addresses in Swanage late on Monday afternoon.
Gaia was last seen by family friend Rosemary Dinch at an address in Manor Gardens, Morrison Road, Swanage at about 16:00 GMT.
She told the BBC Gaia had “pounded” on her door then spent 20 minutes with her.
“She was very upset, she slid to the floor at one point, I gave her a cuddle and she responded to me – I have no idea where she is – she just seems to have disappeared,” she said.
Gaia was said to be wearing a red checked shirt with white buttons, grey and white woven leggings and white trainers.
She has severe epilepsy and she went missing without her medication.
On Saturday, Dorset Police released CCTV footage of what they believe was Gaia running past a house in Morrison Road at about 15:40.
The force said Gaia’s family were being supported by specially-trained officers.