I’ve been trying to bond a trio for the last few weeks. 1 male, 2 female. All fixed.

I had Gizmo (M) first and then Pepper(F). Finally, Loki(F). 

Taking advice from this forum, I waited a month after Pepper and Loki’s surgeries (they were spayed on the same day) before starting prebonding. I’ve been prebonding for about a month (switching litter, living spaces, letting them sniff each other through the grates etc.).Gizmo and Pepper lived together for about six weeks and were quite friendly before her spay so I found their bonding sessions quite smooth and they’re like besties now. I decided to try bonding Loki separately with each  bun before attempting to have them spend time as a trio. The first phase has been going well. Loki went from crazy aggressive to comfortable around the others in our first bonding sessions (I put them on the washing machine, force grooming, slight stressing, shared eating). The next phase which worked well with Gizmo and Pepper, and which I’ve read about on many sites, is to put them in a common area together. 

Well, despite Loki seeming quite at ease with both Gizmo and Pepper on the washing machine, she’s freaking out with the other in the pen. If she was attacking, I would understand and know to separate them and restart the basic bonding, but instead, she cowers in the litter or in the corner of the pen. If one of them tries to come near her, she freaks out and runs off. I did this for the first time yesterday and put all 3 buns in the pen for a few hours. She got progressively stressed and I pulled her out. I thought maybe it was too much too soon. So this morning I put all 3 on the washing machine and they were perfectly fine. 

I waited a few hours and put Loki alone in the pen with Gizmo. She still ran off. I did some forced bonding, treats etc. and removed myself from the pen but she’s still not letting Gizmo near her. I haven’t even introduced Pepper at all.

What should I do? Keep her in the pen until she calms down? Get in the pen with them and force them to interact? Go back to phase one for a while?

(The first photo is at the beginning of the bonding session and Loki looks a bit stressed in the middle there but she relaxed throughout the session.

In the second photo, Loki has her back turned to Gizmo who is grooming himself and is relaxed. If he comes towards Loki. she’ll run. Yesterday, I made the pen smaller and put a hidey hut and toys in there but Loki freaked out and almost destroyed the area while running around and biting at everything then spent most of the session hiding from the other in the hut so I removed it. Not sure if that was the right call but I wanted to force them to interact in a not too claustrophobic way.)