If she's a new hen to the flock; it makes sense as to why she's a "loner". If not, maybe she just likes to roam on her own. If she's not getting picked on, then I think she will be fine. But you should keep an eye on her, because depending on her behavior there could be something wrong, or she could be sick.
Make sure if you notice she is sick you separate her from the flock, so your other chickens don't get sick.
From my experience with chickens, I think she will be okay. I have three young chickens I just brought into my flock and they mainly just go do their own thing away from the flock but they are completely normal and healthy. I hope I was to some help!