Parts stuck in time

I have a 7 year old part who is stuck in the mindset she is still in the past. She will ask for her mommy and is expecting my mom to be here, and while I do still live with my mom she is older now and so this part doesn’t see that as her mom. She doesn’t understand that time has moved forward and also says she wants to go home a lot too because our house looks so different now. So how can I comfort her better? She cries a lot.