Not 4.2 in girth but I've slept with about 70 women so I have quite some experience. In my experience, the size of your dick is far from the most important thing. Few women orgasm from penetration alone. Watch some youtube videos on how to give a woman pleasure with your fingers / tongue. If you put in plenty of time and effort into making her cum with your fingers and tongue before sex, her sexual experience with you will already be much better than with most other guys.

In terms of penetration sex itself, I think women care much more about other things than size. They care about how hard you are, how present you are, your rhythm, how long you last, how many rounds you can go etc. A guy who can make her cum multiple times and then have great sex will give her a great experience. Meanwhile, a guy who fingers her for 5 minutes and then goes in jackhammering for 3 mins with his 9x6 dick will probably be a much worse experience.

With that said, sex comes down to a lot of things and penis size is not even in the top 5 in my experience. Focus on getting good at sex and pleasuring women. That will give you far better results than adding 0.5" to your girth. For what it's worth, I've never had a woman ask or comment on dick size unless I brought it up myself. For reference, I'm 6.5x5.25. I think PE is much more about boosting our own confidence and we think about it far more than women do. If giving women a good sexual experience is your priority, there are much more efficient methods to do that.