Conscious I am a man, so my opinion on the matter is irrelevant to OP, but I can share the experience with implants of a good female friend of mine, Amy.
Amy is currently in her late 20s, works for a big tech firm in Silicon Valley, is engaged to a nice chap and lives what many would call a successful and happy life. Amy has also had implants put in when she was in her early 20s. Prior to her implants she was an A cup, but used to wear push up bras with lots of padding. She was an attractive young lady and had a decently sized bust in most of her outfits thanks to the padding. We were never romantically involved (we each had other partners), but hanging out as friends I did get to see Amy in loungewear sans bra and her breasts were indeed quite small. Nothing wrong with that, but a clear contrast from her normal outfits.
Amy also had really low self esteem and was dating a jerk back then who was drooling over considerably larger breasted celebrities, which was making her feel shit about her own body. She ended up breaking up with the jerk, mostly because he was extremely immature and was not a high achiever like Amy, so they did not get along too well. Amy ended up moving to London for work after graduating, breaking all ties with her ex.
Her first job was very well paid, but stressful and she worked hard. Together with being single in a new city, she felt depressed, lonely and her insecurities were exacerbated. She took up going to gym frequently and toned her body really well. Within 6 months she was very fit, but still single and insecure, despite encouraging comments and support from friends. Towards the end of her first year at the job, she made the decision that she would get implants to feel better about her body. She had saved her starting bonus, was otherwise living a frugal life, so she could easily afford it. She ended up going up about two cup sizes. It was not a drastic change to an outsider, as she basically retained her normal bust size, only that this time she no longer had to wear push up bras for it. Overall, she was very happy with the result.
She met her current partner about half an year after. By that time she had also been promoted at her job and was offered the opportunity to transfer to SF within a year, which she had always dreamt of. She turned into a much happier person and her negative thoughts about herself slowly disappeared.
Now, did getting implants make Amy happy? Probably. Were they essential to her happiness? Most likely not. Being recognised for her hard work at her job, the opportunity to transfer to SF and finding a new boyfriend were arguably more important changes in her life. Does Amy regret getting implants? She says no, though the procedure comes with side effects (she lost sensitivity, had to wait for a few months for things to settle properly, and running with implants is less pleasant than without). They are also not cheap and further problems might arise later down the road (and in any case she will need to have them replaced in about 15 years and it is not a trivial surgery).
Do the implants have a material impact on Amy’s quality of life at the moment? Not really. She got them when she was at a low point emotionally, and while they served their role making Amy more confident, Amy seems to have grown beyond caring about what others think of her tits. I feel like Amy of today wouldn’t have got them, but she accepts she grew out of her older self.
My two cents: think this through really well. It’s not a trivial matter and it is important to view things in perspective. Is this driven by a kink, or would your girlfriend genuinely feel better with implants? Factor in the side effects and the long term as well (she will need a new set in about 15-20 years). If implants are the best option, power to her (and you). There is nothing wrong with doing what she feels is best for her body and people (and especially men) should stop judging what women do with their bodies, including getting breast implants. And on that note, I hope we would stop calling them “fake boobs”. It’s very condescending, especially towards women that might have had them because of mastectomies.
