I seek advice from expert investors/holders/users of this forum,,,,
whether selling my wife's jewelery and investing on bitcoins makes sense?
This jewelry belongs to your wife, and I would have said No that it doesn't make sense only if had she not given you the consent to go ahead & sell her jewelry to be used for investing in Bitcoin, because the fact that she saw the potential in Bitcoin and gave you a go ahead, who am I to say No.
Is it reasonable to invest in gold rather than bitcoin?
Gold was a good option for investment many years ago, but in this 21st century, Bitcoin has taken over the game, and as such I will advise you to invest in Bitcoin rather than Gold, as it has got a good tendency of skyrocketing high after next year's halving.