My MIL lost her husband in her early 50s and she was devastated - he put her on a pedestal and worshipped her and she was lost without him. A friend of his showed an interest in her until he died 20 years after her husband did, although she was not interested and just treated him as a friend (or a verbal punchbag as she could be spiteful). She was very judgemental about others who had lost their spouses but who had subsequently moved on - she thought that they could not possibly have loved their OHs.
She also died about 25 years after her husband and in that time she became an alcoholic, lost most of her friends due to her behaviour and her family was keeping her at arms length due to her hurtful behaviour. She drank because of loneliness - first the missing of her husband and then later, because she became a wreck of a woman who people avoided. It was very sad. She was a very glamorous woman when I first met her before the drink took hold, her decline was painful to see but you could not help her as she used to snarl at the attempt.
But, one thing that she said that struck a chord, not long before she died was that she wished she had grieved for her husband and then moved on and lived a full life. She was still young when he died and grief and the inability to say, that was then and this was now, actually killed her. She killed herself over a long period of time.
I was one of the people who said that women mourn, men replace, and my MIL was uppermost in my mind when I wrote that. On reflection, whilst I do think that is true, maybe men have the right approach? Better to grab at happiness than wallow in grief for a long period of time? Every situation is different, but why should we have the right to judge if people want to make the best out of the cards they have been dealt.
With regard to OP, I still think that 6 months is too soon, particularly as the friend was in both your lives before your wife died, and you have your children's feelings to think about. You may find somebody more suitable in a few months, or you may still like the friend, but everybody needs a bit of time to process everything.