re feral that I brought into home

I brought one of my barn cats in a few months ago. She was very friendly and as I have to sell my farm soon I didn't want to leave her behind. She adjusted quite well to being indoors but seems like she spends most of her time trying to get out. She goes to every window and meows mournfully and has tried to make an escape out of the door a few times if I wasn't careful. If I had been able to stay here I think being and indoor/outdoor cat would have been perfect for her but where I am moving she would never be able to outside which is why I have been keeping her in to get used to it. Today I looked at her and wondered if she is suffering from being kept inside I do play with her and she often gets on my bed and lays near me and my dog. I had such high hopes of her being a happy girl but now wondering Is this normal for a former feral, will she ever acclimate to being happy inside? She is 10yo btw. TIA for any help, I feel like perhaps I should look for an indoor/outdoor home for her but thats probably impossible to find. If I let her back out there is no guarantee that whoever buys my place will take good care of her