Sacrificing your happiness for your gliders happiness is one of the most purest kind of love we has humans can offer. Not only for our pets, but with other people to. And please don't think I'm saying that she isn't happy with you. I'm sure she is very happy when she is spending time with you. But it's the warmth of snuggling up to another glider when they are in their pouch going to sleep, that comforting feeling of knowing your not alone. Or the companionship of having another to play with all thur out the night while my mom is asleep, having someone to eat with. You are like a house guest. You might be over a lot, but their cage mate is always home. Just like the comfort of having your family home. That is what we can not give them.
The group I mentioned on Facebook is a rescue group, but it is located on the US. but the group also offers a free mentor program for new owners. They offer donations to people that take in unexpected rescues that they do not have the funds for, and will even hold raffles and giveaways to help people pay a portion of unexpected vet emergencies that they can not afford at the time. They also have approved vendors that sell safe toys and cage sets. And a lot of them are in Canada. People from all over the world are in this group searching for help and advice. I highly suggest starting there. And if you do decide to keep her, you're not a horrible person, even if you don't get her friend. I say this because of her age. If she younger then I wouldn't suggest keeping her by herself at all.
I would just pay attentions to signs of depression and stress most of all. These things would be bald spots from over grooming, lack of appetite, less active then her usual normal, sleeping a lot more then usually, eating more then usual, behavior changes, such as less social, biting or nipping, or more skittish about noises or certain movements, your barking more then usual, or running in her wheel very long periods of time. All these things and more can be signs that your glider is depressed or stressed out. Excessive barking at random times can be her calling for her cage mates or looking for a friend. I hope this helps you. I can tell you had and have a lot of love for your babies. Finding her a new home could after you had her so long could also make her depressed and stressed out. I would at this way, if your not seeing anything to indicate that she is majorly depressed being alone,I would keep her on me more throughout the day and give her as much of your time as possible. If you are seeing signs that she is lonely and wanting a friend, or you don't have the time to give her A LOT of your attention to comfort her as much, then I would definitely lean more towards the rehoming option. Like I said at the beginning, Sacrificing your happiness for her to live out the rest of her days as the happiest glider she can possibly be, then your making your making your decision out of love instead of greed.