They aren’t really though. It’s a known fact that sex decreases stress levels and is physically and mentally good for you. To get to her age and not have any sexual intimacy does often make people more uptight and repressed. Sex is a release. It doesn’t mean people who don’t have sex are faulty, anything wrong with them etc. But in this one particular case - Gabby is an incredibly uptight, repressed and angry individual. Not having sex is largely contributing to the overall picture. Not the sole thing sure, like you say, friendships etc would make a huge difference. But sex is a big part of that. I don’t know why people are so taboo about sex, it’s normal and healthy to say it’s beneficial to humans.
Plus I don’t even just mean sex - kissing, hugging a partner etc. They all make a huge difference.