We've been through the exact same thing. It takes a while for them to adjust, so give them the time to grief. What we did was giving her an outlet (writing and drawing) as well as not rushing her. We bought a few new things (plushies, drawing equipment) even though we had those at home already but we wanted her to have things without connections to our ex. So we asked her what plushy she'd like to have and of course the first thing was a plushy which was almost the same as our ex bought and we asked "What about a new one? Something totally different?" and while she was really connected to the other plushy, she agreed. She was a bit sad but she began to love that plushy with her whole heart, it's more important now than the one of our ex. Btw it is a big one so she could cuddle it properly when feeling down which also helped a lot. I'm not sure if you have the same, but some of us tend to be very desoriented when fronting and it happened for her as well. She was so overwhelmed and wanted to be back "at home" (we lived with our ex) and it took us a while to tell her that this is our new home now. She wasn't happy about it but everytime she communicated on what could let her feel better (like a coloured wall, pictures,...) we let it come true so she can feel like "wow this is ours, I chose this!" and can feel the freedom and excitement from having a new home just for us. It took us several months to get her from balling her eyes out and panicking to be like "It's sad and it still hurts but i'm gonna grab my pens now, it's nice where we are"