Oddly, 150K is a lot of money and also not a lot of money. It is truly a blessing to receive it, but not much if you were dependent upon it to provide income for your remaining years.
You mentioned that you have 4.8K/month in passive income. What will happen to that in the future? Is it likely to increase, decrease or remain the same? How does that do in meeting your current financial needs?
The easiest and most risk free way to make this money work for you is to buy an annuity. I hate annuities as the insurance companies get to keep your money after you die. This is terrible for your heirs, but for some that is not a concern as they have no heirs. When you purchase an annuity they will pay about 6% in income, so in this case about $750 a month. However, once you figure in that they keep the money, the real rate of return is less than 2%. It is very easy to beat 2% for the sake of your heirs.
For a person that is not super investment savvy, has an interest in leaving an inheritance, and would like this money to provide income I would recommend a mutual fund that is focused on dividends. Some are low risk but high yield, like DGRO (2.37%, $296/mo), others are higher risk but much higher yield: QYLD (11.5%, $1,437/mo) or XYLD (10.9%, $1362/mo).
There are many options so please do your own research or consider consulting with a fee only financial adviser.
Personally I like the idea of QYLD that uses covered calls to generate income. Having used this strategy, myself, to generate crazy returns this could be very lucrative. While the increase in share price is limited, for people seeking income this could be a great fund.