Cat meowing when no one’s home.

For context, I rescued a kitten from the streets awhile back when she’s around 3-4 months old, mother not present (I waited for a week.) She is currently 9-10 months old. I am not able to get another cat due to financial constraints.

I just need some help on how to solve or reduce this. Some days I work from 6am to 6pm so she’s all alone at home, other times I’m homed fully or by 4pm. I got her boxes to hide, she has a cat tree, lots of scratching posts. I also bought toys to hide all around the house for her to find, she has access to the windows to go bird watching.

What else can I do to reduce her loneliness? Usually she sleeps until I am homed but when she wakes up she will meow at the door, or when there is movement/noise outside.

Is this also subtle signs of separation anxiety? 😥