Yes. Mine is a long story. Snowball was a product of two pet shop pigs, one of whom was mis-sexed. The family neutered the Dad, and Snowball lived in a family unit with both her parents. After Snowball's parents died the family tried to bond her with another sow, and it didn't work out, but they had thought the other sow was the aggressor. She probably was.
For reasons I won't go into Snowball was eventually rehomed to me. She was a very well-loved piggy and it was not easy to part with her.
Thinking I could integrate her into the herd I took her, but she was fear-aggressive, and looking back it may have been because the only time in her life that she had met a new piggy, it had gone badly. With my herd she teeth chattered, which set the top two sows off, and they fought (which they had never done before).
I separated them and she seemed content and my herd settled back down immediately, yet she was a bit 'needy' of me, and if anything spooked her she would wheek for me as she had no other pig to huddle with.
After a few months I tried her again and this time Snowball acted submissive, and the others accepted her. It did take her a wile before she showed confidence and relaxation around the others. She lived with them for a year and then started to feel stressed by their presence, even when they were not doing anything. This got worse and worse and she fell out with them.
Clearly she wasn't happy with the sow herd so I split the cage into two and once again she started to relax and be confident once more. She was a piggy who simply felt stressed amongst other sows, even though none of them were bullies and mainly left her alone.
However, after a few weeks of being on her own she was becoming 'needy;' again, which was rather nice for me but really not a good sign as it showed that she craved company, even though sow company didn't work for her.
So I took a big risk and got her a neutered boar. He took an instant liking to her. After a stressful week or so with getting used to him she settled and started showing him affection. She was often to be seen sidling up to him as he slept and lying down with him, and offering friendly nose-boops to him when they were awake. Sometimes she followed him around, so at last I found the right match for her.
Then, in a matter of weeks, she passed away.
But Snowball was certainly happier on her own than with the sow group, but happiest of all with her boar.
I believe guinea pigs can be happier on their own than with individuals or groups that they clash with, or feel stressed by, but I also believe that if they find the right partner they would be happier than being on their own, at least most of them anyhow. I also feel that some cope on their own better than others (some would become very depressed). However many of us will get to that stage at some point where we will find ourselves making the decision not to get anymore guinea pigs, either because we just can't, or we have come to a stage in life where we have decided that once our pets have gone, that's it and no more. This will usually result in one last piggy on it's own, and what to do about this depends on how content you think your piggy is, and it's something I think only you can judge. Do you mind me asking - how old is she?
it's good that you have the option of her going to a friend if she does become unhappy. Your friend may be able to find the right match for her if that becomes necessary.
